And the 'start a thread' nazis are just too much to bear. Prediction: they will add subthreads within 3 years.
Social issues can't be solved by technical means. Just slightly incentivised in some direction (like discord's "this is the third reply, would you like a thread instead?")
But for the resource usage, ripcord https://cancel.fm/ripcord/ already proved you can have a capable client which is super light and fast if you care. This was made by a single person and in many ways is better than the official client.
Well, this was my prediction pre-easy-to-use LLMs, anyway.
Along with syntax highlighting.