I think buying Twitter for data was a blunder big as expecting self driving to be solved by 2015 or whenever it originally was.

It is only clear with hindsight, but now everyone knows that tweets are literally detrimental for LLM style AI for whatever reason. Personally I think it's because tweets are responses without CoT or prompts, or could be also because all its meat is in the shape incompatible with en-US culture, even when it's in English, though all that matters is it's actively useless.