You could do that, but nobody would think an essay was good if it were written with no transitions and mechanically started a new paragraph every few sentences.
1/5. I actually thought it was easier to read in this form. I can't be bothered with articles that have too much padding.
2/5. I think I like features like "paragraphs" that are not possible in this form.
3/5. People can and do use line breaks in tweets, but if you think of each tweet as a paragraph it makes sense too.
4/5. You could do that, but nobody would think an essay was good if it were written with no transitions and mechanically started a new paragraph every few sentences.
5/5. It is interesting how small paragraphs divide a meaning of the whole article and can confuse you, reader.