Premier league is an unforgiving league if you are not good even for a little bit, and these managers have been bad for a while as well. Not like they had a few bad games, in fact Tuchel started the season and he wasn't this bad and he was fired in less games for having even better result, whereas Potter managed the team for so long, with still terrible results. Just because they come thus far in UCL, he shouldn't have been kept. Its good that teams are finally figuring out that keeping the manager is not a big deal, you can fire them anytime you want, if the manager is bad, why wait? No reason to be patient about it at all, they are obviously bad.