Comment by anchpop

Right now they're immature, but I'm hopeful that advancements in ZK-tech will allow practical ZK-rollups. ZKSync already has a zk-evm testnet running (which I believe is based on zk-llvm), so we're close. Currently all the big rollups have master keys which can be used to steal all the money deposited by them, but there's no reason in principle they have to have this. Polygon has permissionless rollups, so I'm quite hopeful that they'll be a viable trustless permissionless scaling solution soon.