> This is a luxury many researchers that work outside of these big tech companies don't have, which creates a scientific power imbalance.

The power imbalance goes far beyond science. Independent research is foundational for platform accountability. An example: when I was working on the Senate staff, before I started teaching at Princeton, a recurring challenge was the lack of rigorous independent research on platform problems. We were mostly compelled to rely on anecdotes, which made oversight and building a factual record for legislation difficult.