Above all else, Twitter (and all social media, including Lemmy) needs engagement. By extension, it needs users and posts/comments. Without these, any social network withers and dies. Twitter also needs to sell ads to make a profit, but those only work when there’s engagement.
Corporate Twitter accounts have their place, but it’s usually only a small piece of the puzzle.
The reports of their shrinking user base and posts are far more indicative of their downfall. While they don’t paint a rosy picture, they also don’t show quite the same level of implosion.