Noted medical researcher and oncologist Dr. Vinay Prasad appears to be one of those people. I don't know whether his statements are accurate but he seems pretty knowledgeable about the system.
metadata on Prasad is important data - if he cannot get basic COVID epidemiology science correct, and if he has a history of promoting a controversial agenda, it is telling gauge of how reliable the information he presents.
A quick look through his post: he cites overhead from several universities as "luxurious" but doesn't really go in to the specifics of why/how NIH and the institutions negotiated this amount. A lot of what he's complaining about seems more like his personal beef with university bureaucracy, which he tries to tie to indirects, but I think it smacks of someone who didn't bother to pay attention to the "people" part of the institutions he works for vs. the technical part of his work (see related post on linux kernel maintainer politics https://news.ycombinator.com/item?id=43037699)
He is wrong about private foundations with their no-overhead/15-20% cap. These grants are routinely rejected by university contracting; or if accepted, it doesn't really count to justifying a faculty's salary (and hence their future career at the institution) as bean counters do not consider the overhead enough to keep the department in the red/lights on when operating overhead costs are considered. The general gist I got when reviewing foundation grant opportunities were "that's nice, haha, but do this on your own time and not department time".
FWIW LunaSea's response is almost identical to what I'd drafted, but then deleted.
caycep's given a much more comprehensive response around the logistics & finances, as well as why someone's recent and objectively alarming public statements can (obviously) be used to assess their credibility and impartiality.
If this is the one & only person you can cite as a follow-up of your "So I don't know who to believe?", then my doubts remain.
https://www.sensible-med.com/p/cutting-nih-indirects-is-sens...