Disabling the HW option in settings/system didn’t work (I forgot to show it in the videos but trust me, it was disabled)
Anyway I did some videos for comparison:
The 1st video is from Brave, private window, all extensions disabled, no other tabs, and behold the stuttering.
The second video is from Vivaldi (same chromium engine), with extensions and some 30 tabs opened, and look at the smoothness… Brave was like this just a few weeks ago.