I can agree with you without absolving ETH of his mistakes. I even argued elsewhere, before INEOS got involved, that there are two paths we can follow. Either appoint a manager who values purposeful possession of the ball and positional play as a means to win football matches, or fully embrace the fact that we're nothing more than a counter-attacking side and act accordingly. In the first case, the managerial appointment should be the direct consequence of a conscious decision to pick up the scissors and the scalpels and, within a certain timeframe, have a squad that will look almost unrecognizable. Otherwise, you take your pick of the currently available top-in-their-class counter-attacking managers (Conte, for example, can come to OT right now) with the hope that they will be able to succeed where both Mourinho and Solskjaer failed. And that is to add a bit of nuance to the one and only trick we have up our sleeves. Sit back, stay compact, put two defensive midfielders behind the sole creator and hope for the best.
People can say that there's not only one way to win titles. I'd argue that it's impossible to win any major honours, if you have only one way to play well. Because we are not even a good transition side, and we have never been one in the last decade. Liverpool are a good transition team. City are, too, when the situation demands it. We are, as described by Pep since he joined City, purely a counter-attacking side. The difference is that Mourinho did it by choice. Both Solskjaer and ETH (and RR for the short while he was here) wanted to implement a high intensity game, but eventually bowed down to the wants and the needs of the squad they inherited. Solskajer completely toed the line after the nightmarish end to his initial six months at the club, and managed to keep this train going until he ran out of short-term solutions. ETH's first season was similar. Scared to death after the opening fixtures, then went back to what his most productive players are familiar with. Just like Solskjaer and Mourinho, the results were OK at first, but there was little nuance to the way we play. Therefore, what we thought was a promising start, was a ceiling. Is it a manager thing? Is it the main players? It's a bit of both. Personally, i would describe us (since the Mourinho appointment) as a glorified WHU. All the money, all the glamour and posturing to cover this simple truth with a bit of stardust.
So, if we think that someone like Conte or Simeone would beat Klopp and Pep in a 90+ race with a few tweaks, bring them in. Otherwise, the road is long and filled with obstacles.