Of course, there are flaws in the players on the team. I don't think Onana is the only one to blame. Erik ten Hag, who cannot read the game and make the necessary moves, is one of the culprits. If there is still no success despite huge transfer budgets, I attribute this to the wrong player transfers and the coach.
Anyone who work in Manchester United has it's own mistake, resulting the poor performance in Manchester United. It's the time for Manchester United to sign a coach from top team, they've tried to sign top players, but all of them mostly flop when they play in Manchester United.
There are only three coaches: Pep, Ancelotti or Klopp.