Trying to fix monopolies by allowing them to continue to exist results in the monopoly continuing to exist. How is this better? There is nothing in a "free market" that disallows a monopoly existing or continuing to exist forever, buying and extinguishing all competition in its wake. It is essentially the end game, ultimate vertical integration and market dominance. You might say some startup is going to "disrupt" these incumbents, until we reflect on all the cool products bought and extinguished by the FAANGs. Basically you're relying on the monopoly getting lazy and hoping there's enough interest and capital available to do battle, all the while consumers get reamed for who knows how long.

Buying upstart competitors ensures that founders and VC are motivated to provide a steady stream of upstart competitors.

Ultimate vertical integration has been tried as a fad on and off. But it did not endure.

None of the FAANGs are all that vertically integrated. Apple doesn't even make their own hardware in-house, do they? (Foxconn makes most of the phones, don't they?)

If the monopolists are reaping excess profits (or having high costs) there's an incentive for new market entrants to come and take a share of those profits.

If the monopolists keep prices low enough that this doesn't happen, then consumers don't have too much to complain about, do they?