I have the same problem! 16" MBP M1 Max. Are y'all using external monitors? I notice is mainly when my MBP is closed and I'm using an external via USBC.
Haven't noticed the same issue with other browsers, but I much prefer using Safari. Might go the Firefox route for a while. Doesn't seem to matter how "complex" the website is - even simple text websites still stutter when scrolling. I thought it was a problem with my mouse for a while!