Haha, sidechains on Ethereum doesn't make any sense to me. A sidechain can introduce extra features and use the blockchain only to settle / for security. It doesn't make any sense to use a sidechain on the less decentralised and secure blockchain of Ethereum while you can have exactly the same features on a side chain of the most decentralised, secure and battle tested Bitcoin blockchain that benefits the biggest network effect.

Blockchains don't scale easy onchain and 2nd layers on BTC will always be better than 2nd layers on smaller blockchains. Ethereum made the mistake to introduce complicated code in the first layer and won't scale or will scale in a way that doesn't make sense, thus I think it is a failed project.

https://steemit.com/ethereum/@michiel/why-i-think-ethereum-eth-is-poised-to-fail-two-major-mistakes-are-made