https://forum.qubes-os.org/t/fonts-are-too-small-by-default/...
> - The overall relative slowness of the system, causing some already slow software to be even slower
Often connected to the fact that hyperthreading is enabled in BIOS (and it shouldn't be).
In general, you should try to ask for help on the Qubes forums. Most problems get resolved quickly.
https://forum.qubes-os.org/t/dark-mode-in-debian-10-vm/3855/...