I'm not in the Ten Hag out camp at all but I find the takes that "there aren't any good options out there" a bit odd. Not only are there proven managers currently out of a job (though certainly I can understand why people wouldn't want e.g. Conte, Flick, Nagelsmann or Mourinho), but there are also a number of promising managers around Europe at smaller clubs that could be worth a try. As examples you've Amorim, Alonso, Motta, maybe even Conceição. In England you could take a flyer on De Zerbi, Iraola, Edwards, O'Neil, Carrick, McKenna, Potter...
I'm not saying all of those are good options but surely you could find a decent candidate from such an extensive list.
Personally I think it's worth sticking with Ten Hag a bit longer as for me he's got the right strength of character to be the United manager and the football we play isn't a million miles away from "the United way" with the right tweaking. However, if we were struggling again next season or the sporting people behind the scenes don't like the way things are going, I really don't think we should cling on because there's nobody else. There's definitely someone out there for us.