That's really not true. Qt as of Qt 6 still supports using native X11 drawing commands and that covers a lot of apps. Tkinter too (and this covers many technical apps which are exactly the ones likely to be used over the wire).
Just last week I was debugging remotely an art installation which uses my software, https://ossia.io and was running on a Pi 5, I compared X11 and VNC and X11 was really much more useable even over the internet.
Just last week I was debugging remotely an art installation which uses my software, https://ossia.io and was running on a Pi 5, I compared X11 and VNC and X11 was really much more useable even over the internet.