Linux isn't afraid to break backward compatible. I'm pretty sure Win32 is going to outlive me.
I had a weird experience where I had to use a device stuck on a 2.6.x kernel, and I was able to run a modern distribution on top of it.
Similarly, running old userlands on new kernels works just as well.
The issue with backwards compatibility isn't with the kernel, but ensuring that whatever you want to run is compatible with the surrounding userland environment. Dynamic linking can break backwards compatibility, for example, but that's an issue above Linux.
I do wish the tooling to make this seamless was better.
Distrobox[1] automates the process of installing popular distros released in the past decade or so in containers.
For games in particular, Proton[2] (a game-specific Wine fork) or one of the Steam container runtimes[3] (for native Linux games) might also be worth a try.
For a non-Steam game:
1. Install and run the Linux Steam client (Steam account required).
2. Add the game to the Steam library: "Add a Game" → "Add a Non-Steam Game…", choose game executable.
3. Right click on the game, choose "Properties" → "Compatibility" → "Force the use of a specific Steam Play compatibility tool", and choose a version of Proton or container runtime (the most recent non-experimental version is probably a sane default).
4. Make sure the selected Proton or container runtime version is installed. These should be available for installation from the Steam library by default. If you can't find them, click the dropdown above the search box in the Steam library, make sure "Tools" is checked, and make sure the "Show only ready to play games" option ("play" arrow in a circle icon to the right of the same dropdown) is disabled.
5. Launch the game from the Steam library.
[1] https://distrobox.it/compatibility/#containers-distros
[2] https://github.com/ValveSoftware/Proton
[3] https://gitlab.steamos.cloud/steamrt/steam-runtime-tools/-/b...
Combine it with QEMU's usermode emulation + binfmt-misc and you can run chroots for other architectures, too.
Second, until Wayland, X11 also created crazy backwards compatibility. You can take run X apps that are decades old.
Where backwards compatibility is poor is in the desktop libraries like those in the GNOME and KDE ecosystems.
Even there though, the old libraries still work. You can keep them around if you want.