It's still orders of magnitude better than X over network, in my personal experience.

I used to watch videos over RDP served from a 300MHz Pentium II with a graphics card from back when having hardware MPEG2 decoding was special. Even today using X applications from my Ryzen 1600X server on my Ryzen 3900X desktop over a direct 40G ethernet link is jankier than RDP was 20 years ago.

X's network transparency is occasionally really useful, but there are newer and better ways to solve this problem. The way it does things made sense for the world it was developed in where asking the host to maintain a framebuffer would have been a massive waste of resources, but those resources are now plentiful.