Perez has had a mixed season. He started the season rather poorly, then had a period of a few races where he performed great and even won a race. The last few races before the summer break, however, it was again under expectations.
Good move by Red Bull?
That is the question. Despite Perez's inconsistent performance, he is doing better than his predecessors Pierre Gasly and Alexander Albon. Partly because of that Verstappen is still in the race for the title and Red Bull is not too far behind Mercedes.
The question is whether there were better options than Perez. Pierre Gasly is doing well at AlphaTauri, but that is no guarantee that he will do as well or better than Perez. Yuki Tsunoda doesn't have enough experience yet and still has to get used to Formula 1. In short: it seems that the most secure option has been chosen.