Once you understand just how massive the overall codebase for "Windows" is, you'll realize how basically impossible it would be for Microsoft to find "ALL" the bugs before releasing. There is code involved in Windows that dates back decades, and there are countless libraries, frameworks and subsystems that exist that are installed only as necessary, not to mention the insane amount of drivers. The main Windows codebase is about 50 million lines of code.
This also speaks nothing about Microsoft Office, which is largely endemic in the Windows ecosystem, is another 30 million lines of code. There are other software packages frequently installed with windows, which overall amount to millions or tens of millions more lines of code...
We haven't even touched on the monstrous plethora of third-party software available for the Windows, which most likely amounts to billions of lines of code. With such a monstrous ecosystem, it is effectively impossible to avoid cases where various software packages don't like to work well together. Windows is a highly extensible platform, allowing software to hook into it, rather deeply if you (the user) allow it, it supports an incomprehensible amount of hardware (all of which have to have their own drivers), and the sheer number of possible interactions of one piece of software with another...well, I don't even think anyone has tried to compute that. Its probably on the scale of the number of neuron interactions in the human brain. Incomprehensible.
I have been a software engineer for decades, been programming since about 7 or 8, and I've at best worked on codebased with a FEW million lines of code, maybe 10 million...and that is extremely rare. Sadly, and this is coming from a consultants viewpoint...I go into companies and help them solve their internal problems with their software, development processes, release and other logistics management for software, etc. Sadly, MOST software is HORRIBLY coded, riddled with bugs, barely maintainable, sometimes just unmaintainable, frequently requiring nearly or wholly complete rewrites from the ground up (simply ends up being cheaper to start fresh, and do a better job from the get-go, than try to fix the horrid messes that most companies sadly have.)
Now...FIFTY million, which doesn't even account for all the lines of Microsoft code that runs on most people's computers, is beyond incredible. Shipping that much code "pristine" and 100% bug free is a literal impossibility. This is speaking with decades of software development and architecture experience.
The VAST majority of software ships with bugs. It is a simple equation of time vs. money...beyond a certain point finding and fixing the most obscure issues, especially those related to various interactions of drivers, libraries, frameworks and the countless pieces of software, becomes too costly to even consider. I have been using Windows, Mac and Linux for decades. None of them are perfect. Nature of the beast...software is really a PITA (says the software engineer!
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I can speak with great confidence that MacOS X is far from bug-free, and in fact in recent years its actually been getting worse. My brand new Macbook M1 Max shipped with OSX 12.2. Day one, it had issues. They redesigned a lot of it, and its BUGGY AS HELL. It tries to treat the entire operating system, and this is a "desktop" operating system, like a phone, so its constantly doing things in the background, burning battery power, constantly waking (even in the middle of the night...I hate completely shutting my system down as I'm always in the middle of things...frequently, my M1 Max will wake a dozen or more times in the night, turning on all my screens for about 30 seconds each time...I have to make sure I turn each one off completely to avoid that problem), and half of these new always-active features are riddled with bugs. They also completely redesigned their display system for the new Liquid Retina XDR displays, and that has also been a disaster. Every time the system sleeps, or even just locks, all of my windows get randomly distributed across my various desktops and displays (I have three 4k displays connected to my main work M1 Max). I have to reorganize every window every time I log back onto the darn thing... I'm on the latest version of OS X now, and they have still not fixed the majority of the issues they introduced with their new generation of hardware, Apple Silicon, and v12 of their operating system. I have been dealing with most of these issues for...well, pretty much since February this year when I got the new mac.
Its effectively impossible to find EVERY bug before releasing. I hate to say it, I loath these kinds of bugs, and these days I'm more affected by MacOS X 12 bugs than Windows bugs, but I hate them both. However as a software engineer, I know the challenges, and just how much time can be required to trace and track down obscure issues that result from the interaction of a lot of distinct and often third-party code. The cost is often IMMENSE, and in the end, I've never known any company to spend "whatever" time is necessary to fix every single bug. After a point, the cost simply becomes too great, at least until more information is gleaned (which sometimes occurs as more users report details about the bugs they encounter.) Its a sad reality...but, it IS a reality. And, as I said, I've at most worked on systems with several million lines of code, maybe 10...I've never been anywhere near the....50 million of windows, or 30 million of office....heck, there are probably a couple hundred million or more lines of code in all Microsoft software as a whole. I can't even comprehend trying to manage such an ecosystem. All things considered, IMO, Microsoft does a better job today, than they did back in the day...Windows 98, ME, and even NT 5 were all kind of disasters. Things got a lot better with Windows 7, a bit worse with 8, and better again with 10. Logistically, Microsoft's engineering teams handle the insane volume of code they have to deal with, coordinate releases around, and fix bugs and security flaws for, rather well...all things considered.
Apple used to do an excellent job as well...but, sadly, the more recent releases seem to be on a steady decline, as more and more bugs seem to be creeping into new releases of OS X. Sometimes they only exhibit on particular subsets of Apple hardware. One of the BIG benefits Apple has, that Microsoft does not, is a near-incomprehensibly SMALLER ecosystem. They only have to worry about their own hardware, and a much smaller ecosystem of drivers, apps, and third party hardware. That is a MASSIVE advantage...Microsoft has to worry about an effectively unbounded amount of hardware, software, and integrations.
Anyway...my take on the "they should fix it all before releasing" concept. IMO, its simply impossible. Even for Apple, despite the monstrous advantage they have given their much smaller and very rightly controlled ecosystem. FWIW, Linux has its issues as well. The unique thing about Linux is, unlike Apple or Microsoft, its maintained by an immense army of VOLUNTEER developers, plus numerous companies that help fund paid developers to work on it as well. When you have millions of developers who can field fixes for issues, they tend to get fixed faster.
(Also FWIW, while this is a potential benefit of OSS, the vast majority of OSS projects are extremely niche, and can't benefit from the kind of dev resource mobilization that Linux can.)