Is There an Alternative to Capping the Level of Ownership of Large Players?

The idea of cap the level of ownership of large players, or making them own only one company in an industry feels really short sighted and problematic. It just feels like we could end up doing a lot of damage to what actually has been a great improvement in the financial markets. I wish that we had much more of a conversation about what's the downside? What's the trade off? Right? And then recognize the reason why index fonds got so barigt because they have a competitive advantage relative to active investors.