I saw someone else's analysis on what reps users of certain rep levels vote for and receive votes from, and it was pretty telling. Save for a few exceptions most 70+ users mostly vote for 70+ users and receive most of their votes from 70+ users, so even without having to name individual users he basically detailed the fact that most large accounts on this platform do in fact engage in heavy circular voting.
And it's not that hard to see when you look at their vote graphs or even just click on who their recent posts got voted on by and which ones were the largest votes.
I do agree with you both in thinking that the current trend of profit maximization and severe wealth concentration has and always will damage the platform's chances as long as it continues.
There’s another way to interpret the rep voting. I vote for people who I’m friends with and want to support. Some of them joined when I joined and we became friends over time. Humans often clump together in similar economic and intellectual circles. The fact that they vote according to those same patterns doesn’t surprise me. The reputation system isn’t that great, but I do often find a correlation between the quality of the comment or post with the reputation score and that makes sense if more people with stake in the system voted them to give them that score.