In the end it depends on the readers themselves. In my story, a lot of people like the MC being powerful, yet vulnerable to some things but there are people who just says that the MC is beta or weak or a coward -_-
For me, an unlikeable MC is a hypocryte. Others, I can still ignore and enjoy the story, but when he becomes a hypocryte, that's it.
Yeah, this is something a lot of authors have trouble with. There are currently 3 VERY successful stories that have gone on to have anime adaptations which feature WAY OP main characters. The common thread between all 3 is that the OP nature of the protag is not used to emphisise their ability to address threats. Instead, it is used to de-emphisise the role of combat threats as a factor in creating conflict in the story. In all 3, Overlord, One Punch man, and Mob Psycho 100, physical conflict is NOT the driving force behind the story. The MCs of all 3 stories still struggle with something despite their OP nature, and the things they struggle with are all a lot more relatable to the common person.
Ainz from Overlord struggles with his built up expectations for himself, he is constantly struggling with trying to fit the role of a "good inspiring leader" that he has built up for himself, and being constantly held to this role is driving him down a very dark path. Saitama from One Punch Man is struggling with the fact that his OP nature makes it so nothing is a challenge for him anymore, and this leaves him with nothing interesting to do since the thing he loves is the challenge of the fight. This leads him to a crippling state of depression. Mob struggles with his Psychic powers causing him to be seen as weird by his peers at school, and even the girl he likes. Plus, he accidentally injured his little brother with his powers once as well. So, he represses his powers and just wants to be able to make normal friends at school despite being seen as a huge weirdo.
In all 3 cases, they have a very relatable problem that they struggle with despite the fact that they are OP. In fact, their OP nature actually makes the problem WORSE in all 3 cases. This is how you make an OP character relatable. Something very casual, something that normal everyday people struggle with, something that really makes sense to become an issue given their situation, has to go wrong for them. And, them being OP has to make that issue worse if anything, or at the very least it needs to not help their case.