Haven't seen Youtube tabs crash like this in like 6 years, now it's happening several times a day. The Youtube UI is also painfully laggy- when you hover over a video it takes like 3-5 seconds for the player to show up and equally as long when I try to pause the video or change settings. When I open the Youtube front page it just shows a blank dark background for a long while before anything loads. Sometimes Youtube tabs get stuck loading, showing only the video with no UI, no way to pause, no comments or recommended videos and the only way to fix it is to open the page in a new tab. It also sometimes seems like a fucked Youtube tab drags the whole browser down, making any websites load endlessly until I close my Youtube tabs.
It's been like this for a few weeks? months? now, but it's steadily getting worse. I assume it might be Youtube fucking with either uBlock users, or Firefox users, or both
This only happens to me if I have more than like 4 youtube tabs open at the same time. If I keep it to 1 or 2 it seems to work a lot better. Also try it in private browsing - maybe you have a poorly coded extension installed that's messing things up.