His point about the missing middle in dating apps is valid feedback about dating apps and all algo-based matching platforms (including news aggregators like this one, although in the case of aggregators it may be desirable).

Designing non-WTA systems is really hard

One system that gets around it is the matching algorithm for medical residency, which is designed to match every student with a space. But (1) this is probably not appropriate for dating, and (2) professional licensing has its own problems.