I think maybe the problem with explaining ECS is that the database-like part you mention is just given a passing mention, rather than being a critical part of the explanation. Obviously ECS is not a database which I think is why people avoid it, but it really helps for understanding it.

Entities are basically tables (just the table, not the data in the table), components are fields/data in them and systems are the SQL you write for them. Its obviously not a perfect representation, especially for components, but it gets the rough idea out there.

Maybe CSE is a better name for it. Its a longshot, but maybe entity being first in the list tricks people into thinking they play a big part, whereas actually they are, as you say, just an ID. Components are probably most important, then systems, then entities