Polkadot vs Sidechains?

What do people think about interoperability across blockchains through Polkadot, versus different kinds of sidechains on a mother chain like Ethereum?

The latter seems a lot simpler and more comprehensive from what I've read, and really accomplishes the same thing, right?

Submitted July 05, 2018 at 01:07AM }
via reddit https://ift.tt/2lVYe4z