my deepest darkest gamedev secret is that i actually don't think ECS is very good. there's nothing Wrong with components, but in my experience pretty much every use case that requires them can also be implemented with inheritance/interfaces. the resulting architecture is more rigid, but rigidity can be leveraged in some really powerful ways. anything you can't change becomes something you don't have to think about changing
ECS is an inherently mushy architecture, and the worst thing that an engine can be is mushy. this is my firmly held belief
I agree with the premise (ECS can get very messy and inefficient really quickly), but I'm just going to flag that an important thing we shouldn't overlook is that its introduction and wide adoption made it much easier for everyone-that's-not-an-experienced-programmer to create games and more freely experiment by constructing new things from existing prebuilt pieces.
(and also freed up team programmer time for other things, I guess, as a positive side effect? Maybe only needing to do some rewrites when the Designer/Artist Frankenconstruct gets too expensive...)