The core issues with Twitter are the Retweet feature and the short character limit. That's also what defines the platform, so that's unlikely to change.

The problem with the retweet feature: Person A starts talking about a topic and post a few tweets. Person B sees one specific tweet, retweet it (with or without comment). People who were following person A see the original tweets. People who were following person B see the reactions to the retweeted tweet, without the original context. Every time the discussion is split with two crowds isolated from each others and everything taken out of context.

The problem with the character limit: given that people link to or retweet a single tweet (120-240 characters I believe), that can only contain a very limited, and often dumb down, version of the actual message being communicated.

That's of course worse given their feed algorithm.