I never understood posts that say: "Onana is worse, but De Gea had to go".
No, De Gea did not have to go. It was a very bad decision to let De Gea go. Why? Because obviously we replaced him with a goalkeeper who is worse! No question about it, Onana is worse than De Gea, this is a fact. We all know that if we still had both De Gea and Onana, then Onana would not play at all. So, obviously it was a bad decision to replace De Gea with Onana, this is elementary logic.
If you replace your car with a car that it is worse, you made a mistake. If you divorce your wife and marry again, and your new wife is worse and makes you more unhappy, then you made a mistake. I have no idea how can anyone claim otherwise! It is just common sense.
On the other hand, we did try to replace De Gea with Henderson and it failed because Henderson was worse. So, we let Henderson go. That was a normal, logical, common sense decision.
To let De Gea go, before we had a better goalkeeper was obviously a mistake, it was a HUGE mistake, it was the wrong decision. Now we have to buy another goalkeeper, and chances are that the new one will again be worse than De Gea.