It seems to me like it’s the other way around. Microsoft keeps comparability forever, which also has tons of negative consequences. With Linux it seems almost like you have to recompile everything anew for each system and each updates, where tiny differences in distributions can break things.
A statically compiled application will run for just about forever on linux. glibc has extensive backwards compatibility too. If you pack your application with its libraries, there's very little to worry about.
Kernel modules need constant recompilation but that's a very separate issue from programs.
Backwards compatibility across releases of the same product, sure. But some products hit their end of life and that's it.
If a product is deprecated, it may not receive security updates or fixes and such. As a user that puts you in a tough situation.
Unfortunately as a user there's not a lot you can do to influence the governance of those products or try to do something to keep them around. If the vendor decides to sunset a product that's it. That's all I am trying to say.
Depends on your choice of distribution. Some distribution will distribute compiled binaries for each architecture. And there are flatpaks that are distribution agnostic.
For your own applications you will most likely use a container anyways and that gives you fairly reproducible builds.
