That's surprising. I tried X2Go a couple of times on multiple machines (always logging in from Windows to Unbuntu 18.04 if that matters, on a local network) and it was horrible. At least a crash a day, couldn't get numeric keypad keys to work, slow. Not sure if I did anything wrong or just had bad luck.. And those are just the basic features. To get on par with RDP it should also do multiple screens properly (i.e. not one big screen, it's not 2000 anymore), drive/audio/... sharing and so on. But I never got to trying that, went back to VNC. Which also has problems but at least it allows me to do work.
Unfortunately the OP is about right (in my experience, for the things I do): if the connection allows it remote desktop should really be like you're sitting in front of the physical machine. RDP does that for me, on the same level SSH/Mosh does that for terminal stuff. I'm not sure what is so hard to get right to also get something equivalent on Linux, so maybe it's really the lack of interest?