If you are concerned about some app, and want to make sure it will run on future Linux versions, you can package or get it as a
snap,
flatpak,
appimage,
docker or even as a
Virtual Machine.
That way all the dependencies can be included with the app and it will run fine even if the host machine has incompatible libs. And the other way around, the app can be updated to use new libs, without negatively affecting the host or other apps.
Or even, when it comes to VMs, run the app in completely different OS. That may be safer, more efficient and robust than keeping a old computer with an outdated OS around. Much easier to backup. Just copy/clone the image.
I mainly use dockers on some of my NAS and snaps on my Ubuntu PC and Laptop. A few VMs as well, for custom programming environments and bookkeeping.