I don't think it needs to be free for over-represented demographics, just open source so that it is clear that the algorithm is designed in the best interests of users.

I like Andrej Karpathy's (I think) idea of training something like GPT-3 on each person and using the derived personality to identify those that you would get on well with (if the objective of the site is long term relationships). I suspect that a large leap forward is possible with something like this, although the technology is probably not ready yet.