Based on my experience from using Ubuntu, it's perhaps more accurate to say that the Ubuntu 19.04 (and earlier) compositing window manager is slow enough to make new hardware feel old. It's extremely noticeable.

The blogpost they link to says as much:

> Gnome Shell 3.32 in Ubuntu 19.04 feels slower than Unity and other desktops. If you have a slow machine then it won’t run smoothly. Perhaps more surprisingly even if you have a fast machine then it still would not run completely smoothly.

(https://discourse.ubuntu.com/t/boosting-the-real-time-perfor...)