My understanding is Twitter always had cultural issues but it was not very different from other tech companies of the time, and what most of us would consider "directionally correct." I have it on pretty good authority from a very senior engineer who left before Elon took over (so no grudges other than, you know, "because Elon") that a lot of the things he said publicly about Twitter's technology was highly misleading or downright false. Like, IIRC, something about them not having CI/CD. Total lie.