> getting hierarchical data based on parent_id

So, an adjacency list (probably, though there are many alternatives, which are usually better). That’s not complex, that’s a self-join.

> trigram functions

That’s an indexing decision, not a query. It’s also usually a waste: if you’re doing something like looking up a user by email or name, and you don’t want case sensitivity to wreck your plan, then use a case-insensitive collation for that column.

> I agree knowing SQL is still useful, but more for double checking the queries from LLMs

“I agree knowing Python / TypeScript / Golang is still useful, but more for double checking the queries from LLMs.” This sounds utterly absurd, because it is. Why SQL is seen as a nice-to-have instead of its reality - the beating heart of every company - is beyond me.