i had this problem as well, the first time i tried to upgrade to mojave. but at some point, apple made it possible to re-enable sub-pixel anti-aliasing.

https://www.howtogeek.com/358596/how-to-fix-blurry-fonts-on-...

at this point, i don't think you even have to do that terminal thing anymore; you can just enable it in settings.

It doesn't replicate what we used to have, it's a half fix at best.

You also have to disable and re-enable it during the Catalina install or it really messes things up.