A lot of leftists like to deny or minimize differences between the genders, and the concept of '"equality" is their end-all-be-all of gender ideology, they say that humans have minimum amount of sexual dimorphism compared to other species.

This makes me wonder, is the underlying idea behind this is that sexual dimorphism simply combos badly with intelligence? Is that it?

If there was an alien species that achieved human-level intelligence but was twice as dimorphic as us (and I'm not necessarily just thinking of difference in appearance but overall differences), is that twice as bad? Are they doomed?