I think this actually kind of illustrates the limits of the "only consent matters" model. Because clearly animals do mate (with each other) and do have ways of signaling that they're interested and whatnot.

It's like statutory rape. It seems odd to say that someone "can't consent" when they did consent. Like, doesn't that very clearly demonstrate that consent is not actually thought to be the only relevant factor at play?

I think that the problem is, within the "only consent matters" model, the word "consent" has been inflated to mean more than just "agreed to it". I think there's 2 pillars to what we consider "proper consent". The first one is straight-up agreeing to it. The second one is a little hard to put into words, but I think I would best term it as something like "being on the same page." A sort of understanding of where the other person is coming from, and what they want out of this. And when the parties are so different, that's impossible.

Teenagers can consent to sex with other teenagers, and dogs can consent to sex with other dogs, but neither can consent to sex with a grown-ass man. So within that framework, the issue is not that they can't consent _period_—it's not that they fundamentally lack that ability. The issue is that the scenario with the grown-ass man is uneven a very fundamental way, and that some level of parity between the parties is also considered to be important.

So I think it would both clearer and more honest if we just said, "Hey, some level of parity between the parties is also important," rather than sticking to the narrative of "consent is the one and only thing."