Ethereum has only one choice to scale, rollups, according to Vitalik Buterin, ethereum’s co-founder.
“In the short term, I just don’t see rollups as being one choice among many things; I see them as being the only choice,” he said, adding:
“It’s basically either (i) rollups or (ii) trusted sidechains, and trusted sidechains are a big betrayal of ethereum values, so…..”
Following a proposal of phase 1.5 and done, the ethereum ecosystem has been debating what that might mean, but Buterin says that can be decided later while implying phase 2 of ethereum 2.0 is perhaps not the best way forward:
“The rollup-centric roadmap is fully compatible with switching to enshrining some execution model at base layer in the future.
We’re not really sacrificing the opportunity to take the base-layer-execution path by taking the rollup path; indeed, phase 1 (which is just naturally really convenient for rollups) was already a necessary step on the way to phase 2. So we already are giving ourselves optionality to decide later.
It’s actually the “enshrined phase 2″ approach that is less forward compatible, because once you have on-chain execution you can’t get rid of it and you’re stuck with its security risks forever [emphasis his].”
It’s not clear whether something has happened in regards to phase 2 and its design but Buterin suggests what Bitcoin Core developers suggested years ago, everyone go to the Lightning Network and problem solved, or here everyone rollup and done.
Problem is no one went to the Lightning Network and how you can have something like Uniswap with Liquidity Providers and automated market makers operate on rollups is not clear.
Optimistic rollups as you may know are a method of data compression where fraud proofs are given only on demand, with some of the data stored on-chain, hence rolled up to the base layer.
These can be fine for simple transactions, except you need to lock the funds first, but for defi transactions there are considerable complexities with such rollups finding no adoption so far.
That can potentially change if the Ethereum Foundation pushes for it, but what is being proposed is a fundamental re-design of ethereum which is quite a bit different from the promise of massive on-chain scale through sharding.