I meant low level in terms of the semantic meaning that HTML can convey. The examples you gave of places where browsers are high-level in terms of what pixels

I meant low level in terms of the semantic meaning that HTML can convey. The examples you gave of places where browsers are high-level in terms of what pixels get put where? I see those as features, not bugs. I'm actually happy that web browsers historically haven't given pages a lot of control over low-level rendering, and I am distressed by the ongoing push by large corporations to increase how much of that control they have access to. I agree with your point about not being able to compose higher-order elements, though.