[wild_preference]

You can already do all of your examples. URLs are autolinked, bullet points just require \n\n, and there's a 4-space prefix for preformatted text.

I think extraneous formatting would just create more incentives to write long, pretentious, streams of consciousness comments where someone just screams from their soap box instead of actually engaging anyone.

[sebazzz]

That is:

https://example.com

- Bullet list - Item 2

    And preformatting which you DON'T want for quotes because they are very annoying to read on mobile

[baddox]

You forgot to hit Enter twice between each list item.