You substituted a different question ("who owns the platform") for the one I originally raised ("how its information and narratives are governed in practice"). Call that a red herring or simply a non sequitur; the label isn't important. It didn't rebut the argument.

You're missing the point of those examples. Of course you can reverse them -- and that is precisely my point! Organisational form or ownership tells you very little, by itself, about whether an institution behaves well. My criticism of Wikipedia concerned how authority over contested information emerges and is exercised. "But Wikipedia isn't owned by an evil oligarch" doesn't answer that criticism.