> You can learn something like ~90% of useful SQL in an afternoon.

It's an ugly little language that one has to come back to and re-learn over and over at different levels of sophistication. Nothing wrong with that, but to suggest it's trivial is a gross mischaracterization.

I think the hard part is not the syntax itself but the shift in thinking: instead of procedural state manipulation expressing the desired end result in declarative set based relation algebra. I see developers struggling with breaking down complex queries in (inline) views / CTEs, thinking they need parameters, when things can be expressed as a queries on another query. Complaining about the lack of reusability, but not knowing about views.

That is exactly what I was thinking. There is such a low barrier to entry with an outsized payoff.