OK, I unzipped your binary in to a couple of desktops including KDE, both X11 and Wayland.
In all cases, the app opened and sat nicely still until I did something. No sign of any jerking around.
If I grabbed the corner and moved it very rapidly, it moved as expected. On desktops like budgie, Mate and even KDE over X11 it followed my resizing quite well. On KDE over Wayland, your application and mine struggle to keep up with my (violent) dragging. I would expect Gnome to do the same thing. I am afraid that is a characteristic of overly complicated desktops like KDE and Gnome, they are just trying to do too much.
To prove that point, I shut down that VM, assigned 4 (instead of 1) CPUs to it and fired it up again. The problem was noticeably diminished.
David