Onana is over rated because he has better passing skills than De Gea but in general, combining all skills of a goalkeeper, I think he is not a better goalkeeper than De Gea. Hopefully Ten Hag will not have to pay an expensive cost by his coach position because of his belief in Onana.
I keep hearing that Onana is good with his feet and that he can pass the ball, but TBH i don't see that when i watch Manchester United's games, he is average in his usage of his feet and his passing accuracy, he is nothing close to the likes of Ederson of City and Allison of Liverpool when it comes to passing accuracy.
That being said, Onana is not a great goalkeeper IMO, average at best, and i think United made a mistake letting De Gea go, the Spanish keeper is better than Onana, De Gea makes unbelievable saves, even though he makes quite a few mistakes too, as for Onana, he doesn't make great saves, but still makes mistakes leading to goals; i'll take De Gea anyday.
Being a goalkeeper it will be about his ability to secure the goal, not about passing. If they want players who are good at passing, then such targets should be delegated to other players and not goalkeepers. Funny I guess, recruiting a goalkeeper just to get a goalkeeper who has a good pass, but in his main task as a goalkeeper in fact does not have good quality. LOL! It doesn't matter about passing, and it doesn't matter whether Onana or De Gea is better because after all, as a goalkeeper it must have good skills in playing as a goalkeeper, because they are goalkeepers and not players who have the task of making passes or assists.