youtube always crash after sometime. i've 16Gb of ram, so it took sometime for me. but the crash is inevitable. in the console, i saw some errors. mostly 401 and CORS to google ads domain. we all know that youtube is doing something shady to catch Adblock users. no adblock, no extension, clean profile and incognito mode. it still happen. this problem is not unique to firefox, it happen to chrome too. relevant question: https://support.mozilla.org/en-US/questions/1435907