While it is true, these features seem to me to be added because Markdown is (ab)used the way it is. The issue is if you are working in an environment where it isn't possible, e.g. on a server where you only have vi/nano, and not even a TUI browser (or if you don't want to use an editor based on electron).

My issue is that you can still have a nice readme (often even giving a better, brief overview) by sticking to HTML-free Markdown.

Gitlab seems to be slightly better than Github, by allowing things like badges to be listed outside of the README, in the header of the repository page.