Has anyone tried building a rollup with native token not tied to the L1?
(Or more generally with no bridges to the L1 at all)

20. hacking @ https://www.spire.dev/ 
previously intern Nethermind, epns.io

Isn't ARB and OP native to their rollup and not deployed to L1?

So $STRK or ETH can be used as gas on Starknet, is that what you were asking? With paymasters, any token could be used to pay for the gas. Should see zksync push that inovation forward.

Yes, but I meant something that is used as the gas token
Should have been clearer