Questions about the nature of decentralization in the network

Lately I have been wondering about decentralization in Polkadot and I have the following questions:

  1. In the future I believe that the total resources of all the rollup owners on Polkadot will far exceed the value of Polkadot itself. Just like Amazon is worth less than the total value of all the companies using AWS combined. Given a scenario where all Rollups have a shared interest, e.g lowering Coretime prices to zero. What prevents them from uniting and passing such a referenda against Polkadot’s own interest with their superior resources?

  2. Given Polkadot current total value, how do we know that there isn’t one entity already controlling 51% of the available tokens? Such entity could remain hidden by owning several separate wallets to obfuscate the fact. How do we know that one entity does not take over the network in the future?