The trauma of that experience has left me with WSL as my sole Linux PC at home.
A masked package is generally caused by something not being stabilized yet, which can be fixed by adding the package to the package.accept_keywords file.
Sometimes a package with known issues, such as security vulnerabilities will also be masked. These can also be installed by adding the package to the package.unmask file.
Your issues were caused by not reading the documentation and taking advice from random people on forums. Ironically portage will actually tell you what you need to do to unmask a package if you read it's output too!
I hope this doesn't come off as too rude, but it's wrong to blame the distro for your misuse of it, especially when there are heaps of documentation and help messages in the output!
Out of curiosity, what is your use case for this particular Gentoo install? 15+ years is a long time to keep the same machine running.
Physically there is nothing left of the original hardware as it has gone through many generations of part replacements, Ship of Theseus style. It's the OS image that has survived through all this. My /home which I keep separate is another 10 years older.