Why are we just taking for granted that the Youtube acquisition wasn't anti-competitive? There is a reason that Youtube hasn't had any competitors in the 15 years that Google bought it. It's because video can't be done as cheaply as Youtube does it, unless you have an entirely separate industry propping it up. Selling on product at a massive loss and propping it up with a separate industry is anti-competitive.
Nobody can compete on Youtube-style video unless they first create Google. If that isn't true, where are the competitors? TikTok is the first one to even resemble a competitor, but it took 17 years and even that isn't really the same thing.