When contrasting sharding with multi-blockchain (multi-token) solutions, I heard a lot of people say that the multi-blockchain solution is not secure because smaller blockchains would be vulnerable to 51% attacks from nodes which run the larger blockchains. But I think this is only true for Proof of Work blockchains.
It doesn't appear to be a problem for Proof of Stake because a hacker would have to buy more than 50% of all 'sidechain' tokens in order to bring down that sidechain; by the time the hacker acquires that many tokens, they would lose the incentive to bring it down... The hacker would also be the biggest shareholder of that token so their incentive would be for it to go up and not to hack it.
Given that Ethereum is moving to PoS, wouldn't it make sense to go with a multi-blockchain solution (each ERC-20 token gets its own chain) instead of sharding chains based on other arbitrary attributes?
