> Companies should get kneecapped if their market cap gets too high?

Yes. They should be broken up because competition is good for consumers and society. If we had functional anti-trust enforcement Google would not have a near-monopoly on search ads where they own both the ad inventory and the marketplace where you have to buy those placements.

Then you'd have two (or three, or four) companies that Larry owns 5% each of that are collectively worth $4T.