The squad is the main problem here. I always say that. They need to strengthen specific areas to be more competitive than this. Defense comes first for them considering their literally not being able to defend their opponents. The first transfers should be targeting this area and then they can look for how they can score more goals.
I think most people blame Ten hag every now and then because they believe that as a good manager that has been in the team for sometimes now he is expected to bring a change in the team but it seems the Manchester United team is going from bad to worst up on his arrival. Personally I blame the coach most times because of the numerous wrong substitution he has made in Manchester United games that has ade the team to drop more points and his inability to master a particular formation that would have helped the team to get back to good form aside that, I think most times the players are the Major reasons why the team isn't getting better anymore.
For me I think the team needs to strengthen the squad in doing that they need to path ways with most of the players because they are not doing anything for the team because watching them play they play without love and support for the team and players that you see with that attitude can't get better no matter the coach they have I believe this is the only problem in the United team. The management should bring in a good defender, a good striker and a powerful midfielder that will strengthen the performance of the team and they should open doors for some unserious players to leave next season I believe the blame will be reduced when that is achieved.