Funny. A couple of months ago r/btc was still criticizing Bitcoin Core for scaling with what they perceived as federated sidechains. Now sidechains appear to be one of the main innovations coming to Bitcoin Cash.

Also the motivation behind implementing drivechain reads like a checklist of what they critizied about Core when SegWit was still debated (ie. protecting Bitcoin from hard forks, ignoring ideas...)

I digress though and I still need to read through it from a technical perspective.

But you definitely got a good point. The alts aren't sleeping. Ethereum also has some interesting developments going. And I'm sure some of the other alts as well.

Keep in mind though that a lot of these innovations are not exclusive to each respective blockchain. Sidechains have been in the works for Bitcoin even before Bitcoin Cash entered the stage. Vice versa Lightning Network can be implemented on any blockchain that doesn't suffer from transaction malleability.