This is disinformation. Blackrock and Vanguard manage the accounts of people who own these. They themselves do not own the shares. It would be like you saying you don’t own your 401k, Fidelity does.

There are still control concerns, if blackrock and vanguard started throwing around weight more they’d have a lot of power as investor aggregators. They do “control the vote”, in theory, on a lot of the economy through their aggregation. AFAIK they don’t use this much because it’s not practical for their funds. But framing them as real owners is the kind of boogeyman crap.