good is the enemy of excellent. X11 works for most users (almost all the users?) well. You can see that with the adoptions of other standards like the C++ standards and IPV6 which can feel like forever.
Another thing I think one of the X11 maintainers mentioned iirc is that they have been fairly gentle with deprecation. some commercial company could have deprecated X11 and left you with a wayland session that is inferior in some ways.
gocryptfs is very fast for me. i have a file with about 5600 lines and i detect no difference when opening it under encryption and not under encryption. but in gocryptfs each file is encrypted separately . so you could get some information about the directory structure. but the name of the files and folders is encrypted ("archive" for example turns into something like "AaL6P86WWMnqQkMYnsRBXg").