The "point" or benefit of a twitter thread as opposed to straightforward longform is that each tweet (sentence or paragraph) can stand alone (in terms of liked and retweet circulation) as well as being a part of a broader piece.
"Can" or rather "could", but never really does in practice. Take away the thread, and 99.99% of mid-thread tweets lose all meaning. It just makes things awkward for the sake of it.
It's funny, I mean, you're not wrong, but there was a period when I wrote a lot of twitter threads, and I enjoyed the challenge of making each tweet stand alone. I think it made me a better writer. But yes, many don't take advantage of this.
