Also, can you still boot Ubuntu from a flash drive or DVD and test compatibility that way?
Linux works well with older systems, too. My laptop is 9 years old and going strong. The first four years under Windows, the remaining 4+ under Linux.
“Also, can you still boot Ubuntu from a flash drive or DVD and test compatibility that way?”
Yes. Really old PC BIOS may not support booting from USB, but surely all support booting from DVD. Running from a DVD is slow, but at least it will verify the OS and hardware are compatible.
I installed Red Hat over 10 years ago, and that did require enough technical knowledge about partitioning that Joe Sixpack’s mother probably couldn’t do it. That computer did not have enough RAM to be practical (16MB!) even though it was enough for Windows 95. When I returned to Linux years later on a better PC, installing Ubuntu’s “Gloria” was a revelation of simplicity. I’ve been hooked on Linux ever since.