Polygon announced their new vision in “Polygon 2.0”, a sort of mash-up between the Optimism and Arbitrum stacks along with Cosmos’ Interchain security. Essentially, you have 4 layers: Staking, Interop, Execution and Proving
The staking layer will be where validators stake MATIC (how Polygon PoS works today). Then you have the interop layer which will act as the bridge for minting assets to/from Ethereum. All chains in the Polygon ecosystem that utilize assets from Ethereum will use this shared bridge which has the benefit of allowing for easier cross-chain communications. On top of this is the execution layer. You will have the zkEVM which uses Ethereum for DA, the PoS zkEVM which is a transition from the current PoS L1 that will use an off-chain DA solution (assuming Polygon’s DA layer) for DA, and then Supernet chains, essentially appchains like in Cosmos’ Interchain Security or Avalanches Subnets.
While all of these will use MATIC staked on L1 they have different tradeoffs. The zkEVM will use Ethereum for DA and will be both the most secure and most expensive. The PoS zkEVM will use Polygon DA (secured by MATIC) and will just post the proofs to Ethereum, allowing for cheaper fees at lower security. The supernets are re-staked MATIC (and the option for additional tokens) for appchains.
This approach is a common theme these days, and further cements ecosystems into their own silos. You have the Op stack where chains will be able to interop with each other, the Arb stack, the Polygon stack, and others. Interoperating inside their ecosystems will be simpler while outside is harder. While all of these us Ethereum in some form, it’s notable that they all are diverging into their own communities with their own social consensus.
I think it’s clear now that L2s do not, and will not extend Ethereum’s social consensus, but more so compete against each other.