This is most likely because so far we haven't heard any rumors about Manchester United looking for a new coach, so I really think that with what Ten Hag has built, it is appropriate for him to be given 1 more season to continue what he has started, everything needs a process. and Ten Hag is going through that with Manchester United.
Ten Hag has done his best, we can see that building a Manchester United team which is already quite down is not an easy thing, several coaches have coached Manchester United before but all of them failed so this job will not be easy, everything takes time and a process.
I think Ten Hag should be kept, I really want that and I still believe that Ten Hag is able to make Manchester United better next season.
Currently Manchester United is evaluating ten hag's performance so far, I think previously ten hag's chances were retained by Manchester United 50/50, but after Sancho is reportedly going to be sold by Manchester United then it is 90% likely that ten Hag will remain the coach of Manchester United next season, two seasons ten hag has been at Manchester United and 2 minor trophies he managed to give to Manchester United at this time, what you say is true, it looks like Ten Hag needs a lot of time to be able to rebuild the team, but with so many star players in their squad right now, it seems that Ten Hag should have given something that Manchester United should be proud of, from than just the Carabao trophy and also the FA Cup.
Manchester United is a big club that has a long history of glory, so it is quite natural for Ten Hag to shoulder the responsibility and also the great expectations that he must meet at this time, the failure of some Manchester United coaches before Ten Hag should be a lesson and experience for Ten Hag, but in fact after Spending 360 million euros ten hag was not able to bring Manchester United better than the previous coach.