Yes ..there are a whole bunch of them..
1. David perell— runs a writing cohort
2. Jack butcher — sells design related products
3. Dru riley — runs a market research based newsletter
4 steph smith — sells content related info products
5 shaan vp — sells a writing course
6. Dickie bush and nicolas cole — runs a writing cohort together
7 borrowed_ideas — runs a investment based newsletter
8. Nat eliason — runs a defi course
9. Preeti kasireddy — runs a ethereum developer course
10. Aja_cortes — sells fitness related products
11. Codie sanchez — runs a business based newsletter
12. Packy mccormick— doesnt sell a course..but his newsletter makes 6 figures just from sponsorships ..he gets his audience only from twitter
13. Lennysan — runs a product management based paid newsletter —gets audience only from twitter
14. Seananthonysays— sells a email marketing course
15. Sahilbloom — runs a curated newsletter and an audience building course

All these people make 6 figures just from either newsletters or info products

This is just a sample..then there is “agency twitter—selling courses related to lead generation ” “copywriting twitter— copywriting courses ” “fitness twitter—fitness related courses” “saas twitter” etc…many of them making 6 figures per year just from twitter..