I think what they did with Rangnick was just pure arrogance and a waste of everybody's time, they should have made the most of that period and listened to him but their problem.
Bang on. I know there are a lot of detractors of him on here, and admittedly he himself isn't that great of a coach - arguably down to his character - but exactly that character and his deep knowledge of football made him such a great appointment longterm. The guy built and established the whole RB franchise, they churn out players and managers at Liefering, New York, Salzburg and Leipzig on the trot. Before that he turned a ****ing village club into a Bundesliga mainstay in Hoffenheim - they even ended up in the CL once iirc. His and Helmut Groß school of football has influenced endless managers, even if they don't hail from the RB school.
His rant about how **** that club is was absolutely spot on in hindsight. I'm also pretty sure it wasn't just Utd who let him go, but that it was very mutual. Apparently he even told Sasa Kalajdzic to not go there at any cost. I rate Ten Hag but his statements about him not needing Rangnick seem like arrogant bullshit in context of their ridiculous recruitment this summer.
Right before and for some time during the Ole era their squad looked very close to competing with a bit of binning and proper signings. Now it just looks bleak. Their only CF is a 37 year old Ronaldo who wants to leave and is way beyond it, Sancho seemingly can't cope with the pressure and physicality, Rashford is a worse Walcott, their CM is beyond diabolical, no quality fullbacks, Maguire as their marquee CB and a GK who can't kick a ball. In Rangick they had the right guy to get them on track but they ****ed it up.