I know that in my younger years I would get a lot of flak for converting .rst files into .md when I joined projects.
(As I got older I just stopped seeing .rst that much)
Now we have markdown which is unable to express the structured parts, with a flea market of less-good extensions, some raw HTML snippets, and in general have lowered the bar to not even attempt the things rST is capable of.
Instead of rST, the markdown ecosystem is leaning toward "some fenced code blocks are magic", with user-unfriendly goop in them that is hidden by the UI (when one happens to use the one blessed UI for that flavor). And that approach can't solve inline directives.
It's a shame because reST is almost as easy on the eyes as Markdown and is much more capable without being too much more complex.
Why would you do that? Seems terribly impolite to join a project and start breaking things...
Learning is a process.