> Oh, that's why that kept happening on my Macbook pro? I thought I was loading a broken site or had too many tabs open like I always do.
That's what I thought as well, but apparently it's something to do with the compositor and FF redrawing the whole window instead of just relevant pixels or areas - which provokes a lot of unneeded calculations -something specially damaging for users that have scaling set to more space (effectively a higher resolution).
That was my understanding at least, when I first learned about the bug many months ago. I followed the development for a while with no (public) improvements and now I just wait for news about the issue or something, but all FF related news so far have been about new features or products.
For me adding "Auto Tab Disard" [1] (a Firefox equivalent of The Great Suspender for Chrome) has reduced my FF memory/CPU footprint by 10x. It defaults to 10 minutes which is usually long enough where you've mostly forgotten about the tab, then it will refresh when you focus on it. A feature fortunately becoming native to FF. I don't seem to have the previous performance issues anymore but I'll be looking for it now.
[1] https://addons.mozilla.org/en-CA/firefox/addon/auto-tab-disc...