Why Twitter doesn't at least try this feature in an opt-in way beats me.
It makes it harder for people to reply to the chain (do you reply to the first or last?). The same problem exists for retweets; if someone retweets a tweet partway through the thread, it doesn't behave as neatly as you describe iirc.
Also, there's just a difference for the author. Writing a paragraph of text like this comment, where I get to go back through it and edit it as I go, add and remove paragraphs... It results in me creating a more carefully edited and thoughtful piece of writing. With the tweet threads, someone either has to write the tweets one at a time (and can't edit previous ones) with twitter dictating the breaks, or they have to do paragraph-oriented editing locally, and then figure out how to break it up correctly for tweets (which is non-trivial actually! URLs take up a difficult-to-predict-naively number of characters, so it's not naively 140 chars if you have urls, etc).
Basically, twitter's model facilitates a different sort of writing and reading than a single long post does, even if they are just both a bunch of letters.
If you were limited to 280:
Some discussions have nuance that cannot be expressed in 280 characters.
Yes, when expressing a simple idea or an idea you understand very well, you should be able to do so concisely.
However, when providing information to someone else about a complicated subject, or trying to
It's artificial scarcity, that doesn't really benefit the reader that much, and certainly not the writer.
This medium provides the good sides of Twitter with the good sides of a federated system, where content discovery is still done organically through people. If experts want something as easy to use as Twitter _and_ have the possibility of having more space, I feel they should migrate to it. Or anything that uses ActivityPub really, like Write.as or Plume
There's also the whole indieweb movement, with micropub, microformats and stuff that anyone can play with, like with Micro.blog.
All options that give more control to the user
This isn't a good thing. Who's an expert vs an amateur just having fun? Who's just musing idly while sipping scotch versus gone through several drafts and really put a lot of work into this? Who's passionate, if wrong, vs a troll and a provocateur?
It's fine for all those things to exist, it's not fine that we can't tell the difference and then amplify an unsuspecting chunk of them to a massive audience.
“I didn't have time to write a short letter, so I wrote a long one instead.”
― Mark Twain
Ofcourse, its about how you're interpreting this information - by inquiry or face value (which can be dangerous).
I was skeptical about feed quality getting diluted when twitter increased character limit to 280 -- fortunately, for me, it hasn't (as much as I expected) with few exceptions.
Or not use Twitter at all.
Yes, when expressing a simple idea or an idea you understand very well, you should be able to do so concisely.
However, when providing information to someone else about a complicated subject, or trying to provide reasoning for something, it's very easy to need more words.
There's a reason that encyclopedia entries are usually much longer than 280 characters even though they're expressing a single point that supposedly the author knew very well.
When answering a question that requires referencing multiple other pieces of information and where the answers aren't certain, you even more easily overflow 280 characters. For example, saying "I started with a ballpark estimate from these facts (fact, fact fact), and extrapolating with this assumption, you get to this. However, if you extrapolate in this way, you get a slightly different answer" etc etc, expressing that uncertainty, the assumptions, and alternatives are all _very_ verbose.
There is also a huge issue where people get tricked into thinking familiarity = knowledge. Reading tons of 280 char texts seemingly synthesising complex ideas in "single bite" portions is a problem, it makes you think you know something when in reality you just absorbed 280 characters of "facts" without any context or substance, it doesn't better you. Especially on twitter, which must be the most polarised and polarising medium out there. It is level 0 of knowledge acquisition.
> You must linger among a limited number of master-thinkers, and digest their works, if you would derive ideas which shall win firm hold in your mind. Everywhere means nowhere.- Seneca