The key here is that the environment of near-zero interest rates these services proliferated in is over, so there is a drive to wall up and monetize their content more aggressively. That will probably fail, because all value they had was in community interaction. Who would want to train an LLM on post-2023 twitter content?
Because Big Tech demands big profits. They can not exist in worlds where they can not have a monopoly or oligopoly.
Smaller companies and ISVs, on the other hand, will be better off if their market is commoditized. They won't have to spend so much to compete in R&D, they just need to find each the best way to serve their (comparatively) small customer base.