Honestly can't see people dumping their pcs due to 'incompatibility.' Windows 10 support ends officially in 2025 but it doesn't make it unusable for as long as the computer and programs are working as they should. My parents have a laptop from around 2018 that came with windows 10 and its not windows 11 compatible. They are going to use that thing until it can run no more. It's essentially a more functional iPad.
Most people who are replacing computers for windows 11 are either college students, people who work on large projects or people who are gaming from a very old set up. As long as everything works with an internet browser and can install proprietary software then most likely they will keep it until the equipment gets too old.