What does ‘survive’ mean? Not go into administration or something? Of course the club will go on, but whoever replaces him will not be as good as him, hence him being irreplaceable (of similar quality, of course). We can replace him with Tom Davies, we will just be an even worse team, is my point.
Fans are ridiculous sometimes anyway. If half of you guys could ‘leave Man United’ at the moment you probably would. But fans don’t change teams. Players do, and there was an inevitability that Pogba would want to leave. Some sound so begrudging of it, but it’s probably the natural order of things now, if true. That might change with a new manager and sense of direction, but if not, there is no reason Pogba would want to spend the peak of his career here.