Windows may die (don't hold your breath) but Microsoft will only fail if they fumble the transition... a huge proportion of people "abandoning" Windows will take their Office 365 subscriptions with them to Mac/Android/ChromeBook & MS can leverage those to sell AI services and other cloud-based services. Windows is so huge that it will be years - if ever - before it, or the huge ecosystem it supports moves on, goes away, but MS could certainly start to kill it off in the consumer market.Microsoft is destroying Windows in a way that no other company could.
Let's praise Microsoft, folks.
Windows has peaked - if you look at the wider computing market, it's surrendered the mobile market to Android and iOS, Linux rules the supercomputer market and has a growing share of the server market (with many modern 'software stacks' being based on open-source Linux/Unix tools). They're strong in the PC market, but that's lost a chunk of the low-end to mobile and Chromebook, and they're at best holding their own over Mac. Gaming is a strong point, but it's not like the other consoles and multi-platform Steam aren't serious competition. Their unassailable point has always been "corporate" - but that's partly dependent on a legacy lock-in, which won't last forever. MS may look huge today, but there has been a dramatic change since the good old/bad old days of the 90s when it looked like wall-to-wall Microsoft.
Computer hardware has got so powerful that - certainly for 'personal productivity', general development and casual gaming - there's enough headroom to run everything from inside a standard 'runtime' application using scripting, emulation and virtual processors. The most obvious examples are browser-based apps and their widespread (but less-obvious) cousins using Electron or similar (Visual Studio Code being a prime example). The idea that applications need to be tied to specific hardware and OS features is a thing of the past.
One thing that Microsoft is doing with Windows 10 & 11 - is dumping a lot of legacy compatibility which, in the past, has been a major contribution to "Windows lock-in".
Mind you, a lot of the above reasoning applies equally to Mac OS... The future of consumer operating systems may well be just enough to support a HTML5/JavaScript/WebAsm runtime (the latter being quite capable of running code compiled from languages like C# and Rust, if you hate Javascript).