I think this is somewhat by design. The stated goal is that all checks are ability checks, and skills are really supposed to represent specializations in an area that provide a fixed bonus to that check. To that end, I think they're doing a poor job of conveying that idea, but it may also explain the abundance of knowledge skills, to reduce the idea that if you don't have the "swim" skill, you can't swim.Regarding Knowledge skills, I think that having lots of them could be useful, but 5e in general suffers (at least thus far) from skills not doing anything specific and instead just being rolled when a somewhat-related situation comes up.
From the previous thread:
I don't know if you saw it, but I would be very interested to hear your ideas on my last thoughts in the last thread RE: combat superiority dice.