Ten Hag is a wasteful coach. During his time in United was when United spent a lot of money and got no result despite the huge amount of money that they have invested in the club. De Gea was sent out of the club by Ten Hag and the management had too much believe in him to the point that they gave him total control on making decisions and buying players of his choice. That was what crumbled United financial strength.
Ten Hag’s choice of signings was really terrible, I can’t believe he spent so much and made little impact before getting sacked and Manchester United struggles continued with his signings. One of the mistakes United made was sending De Gea and Ronaldo away from the club but United supporters will never agree, Ten Hag was one of the problems and not De Gea or Ronaldo!
This was one of the main reasons why he was fired as well. I agree that he was a bad coach too, but he was decent enough to win some cups so he could have kept his job if he had a good squad, because the team wouldn't be doing this badly if he wasn't horrible at transfers. Imagine if they used the same amount, but instead got great players, then even ETH would have taken this team to top six, because they spent enough money to be a top six team.
The difference between right now and a scenario where they are sixth, is the fact that they paid 100+ million on transfers that worth like maybe 40 at most. If Erik Ten Hag was capable of getting good players, or even just these players but for what they really worth, then it would have been fine.