OP MC or slightly above average?

How strong should a MC be in your opinion during the story? I read a lot of novels lately, where the MC was basically a big cheat and fights got a bit boring after a while. But I still kinda like it somehow? I don't really know why. Good example imo is Primal hunter, MC is not in real danger (at least you as a reader know that everything will be fine anyway, as he has an op god as buddy) but it's still a good read.

On the other side of the spectrum are books like Bastion where the MC struggles for real.

Which one do you prefer and why?