I don't get the arguments for bioessentialism

[Umbran]

Well, if you want do that, then you do not need to have non-human sapients at all.

Not just "if you want to..."

It is, "if the differences between humans and non-humans are too small, you don't really need the non-humans."

You know how everyone complains that non-humans just seem like humans in costumes? Well, that means your non-humans are not distinctive enough.

I think the point of non-humans are that they are some way different than humans, otherwise they would just be humans!

Right, but then you have to actually make them DIFFERENT. Being a little stronger faster, or tougher doesn't really do it.