a defense of it, from someone who's not in the cryptocurrency scene:

blockchains are useful because they offer decentralized centralization. Ethereum has no policies, no embargoes, it's a neutral platform. this is because everyone can agree that what's on Ethereum is canon, and everyone can access Ethereum (except for how pricey gas is.)

this is the opposite of federations where servers host their own state, with their own terms and conditions or API keys. everyone can agree on putting things in one place. I think that bit is genuinely useful.

so the major problem is that gas is expensive (and PoW is immoral, but I'll leave that for another time.) gas is cheap on altcoins, but nobody (rightly!) trusts bespoke altcoins because they're too small to be secure.

this L2 stuff is the solution, because rolling up to Ethereum keeps the not-an-altcoin L2 chains honest, along with verifying that their aggregation or challenge protocols or whatever are secure.

whether you find a scalable blockchain useful or not is a different matter, but I think L2 protocols will get it there.

That's just too funny: "ethereum has no policies". It had a superb bail out of the initial DAO in 2016, which was deemed too big too fail, and lead to a fork of the chain. So let's not pretend blockchains are neutral immutable ledgers, they exist purely for speculation.

Can you clarify what "not in the cryptocurrency scene" means? You seem to be a proponent.

I haven't invested in cryptocurrency besides a small amount of Bitcoin more than half a decade ago (which I subsequently got locked out of.) I've never worked for any company doing anything blockchain-related. I was enthusiastic early on (2011) but became jaded by seeing how environmentally awful Proof of Work is, and how PoS has stalled.

I find trustless/decentralized protocols intellectually interesting. I didn't count myself as a proponent because I don't have skin in the game.

Fair enough - thanks!