Twitter has a lot in common with writing poetry. I think it can be a good practice, depending on one’s goals. But I agree with your general point about reading a lot. I think it’s important to read a lot of different styles/genres: fiction, academic writing, journalism, old stuff, new stuff, translations, great literature in various languages, ad copy, so on. Most good writing is about conforming/mimicry and being especially considerate of the reader. Exceptional writing is a different thing. A lot of bad writing comes from regular people trying to write exceptionally. It’s hard to learn to write dumber, but thankfully the internet lets us all practice a bunch. Whether we like it or not, most people prefer Stephen king to Henry James or Proust.