one of the worst idiocy of web design is to have a Header such as
h1 that links back to its entry in Table Of Contents. Such design is widespread in 1990s and early 2000s. but today, you can still see it, especially in the geek circles. ⁖ most of FSF GNU's doc in HTML are still like that, as well lots Tex/LaTEX converted docs.
similar idiocy is for it to link to anchor on the same page ⁖ 〔http://example.com/index#sec1〕 or link to top of page.
the problem is that, when you see the header as a link, you don't know if it takes you to the section detail, or takes you to Table of Contents, top of page, or reposition your page to anchor point.