No and no. Im not equivocating anything (far from it actually, my post is very blunt about its contents so unless you're misunderstanding the meaning of the words you use, you're wrong) and no, I'm not complaining about males in manga so if you're gleaming that, then you're projecting your assumptions about me onto my words.
Either way, not the case. Now if you wanna talk isekai and why its MCs are so often way stronger than they need to be? I'd wager a mix of wish fulfilment and because having a weak character in a new world limits the things you can do with them, and nobody wants to read a hundred mangas about farmers in new worlds.
Lets talk about why you feel that way about male leads getting harems all of the time. That's because your post just screams "I only read shounen and seinen manga" and the demographic for those mangas are, you guessed it, mainly males (not to say there aren't females reading, they just aren't the target audience). Males typically identify more easily with a male protag and I'd wager the majority of them are turned off at the prospect of homosexual relations, thus forming our male MC with added harem situation.
There are plenty of reverse harems out there, they're in shoujo mangas. I don't know of any specifically, I don't read very much shoujo at all but I'm told that they do exist. I'm sure there are less of them but that's probably down to the differences in things that the genders seek from their entertainment. To clarify, I'm fine with female leads but like male leads they have to be well written characters who happen to be [blank] rather than strong [blank] character.
Two final things, I don't think male leads are overly scrutinised, I just made the comparison that female leads aren't scrutinised as harshly. I think they could all do with some higher standards, that way we might have some better written mangas out here. Secondly, I'd like to repeat that this isn't the place for your wish fulfilment of "I want more whamen in my mangas to be real strong n mary sue for me pls more wamen im respectable pls notice my reppect". Keep your gender politics out of here.