A project that is centralized in Vitalik hands, was premined and was rolled back like Ethereum blockchain, is not a decentralized project and blockchain.
If Ethereum can not be decentralized, other altcoin projects and blockchain are only more centralized than Ethereum.
Just because ETH is centralized (even more so with PoS), it doesn't mean that every altcoin is centralized. That's a bit dismissive, don't you think?
Are Litecoin, Monero centralized? Just to name a few...
Regarding Lightning, necessity is the mother of invention.
When on chain transactions are dirt cheap, there is absolutely no reason to use L2:
https://litecoinspace.org/Bitcoin was like that 15 years ago...
If Litecoin became really popular, then it would face the exact same scaling issues.