In my experience startups typically pay more than other well established organizations, at least for Design/front-end roles. Agencies and Enterprise is typically where the low wages come from.

This doesn't factor in Silicon Valley. SV is an entirely different animal. The cost of living there throws the math way off. I can imagine that those wages are typically very low. $200k in SV is comparable to $70k in most other cities. This is why it's beneficial to work remotely for a SV startup and live somewhere more desirable.

I think we're conflating all startups with SV, which shouldn't be the case. Certainly folks joining SV startups IN SV are being taken for a ride.