Why is regular text in HTML bigger than some of the heading types?

Question

It seems odd to me.

Answer 1

the headings aren't for making the text bigger, they should mark the most important element (h1) the text only get big because of the browser default stylesheet

Answer 2

some are bigger, some are smaller. <h6> is smaller, of course, but it is strong and bold, and it has its role in hierarchy and outline of the text.

Answer 3

it shouldnt be odd in any case the heading types are bold unlike the regular text

Answer 4

because that line should be important