I think the person you're responding to was talking about Bitcoin L2 chains, probably more specifically the lightning network.
I actually agree with that about Bitcoin.
Web3 is generally done on EVM or cosmos chains, some of which are L2s (and some of which are loosely considered L2s). But most of them are still separate chains, so not L2s in the sense that the Lightning network is an L2. If you're looking at EVM chains, then L2s are certainly required to handle significant throughput, but the "lack of transparency" mentioned by GP isn't an issue with them.
Especially considering that it is being independently developed by three organisations as an open source protocol that offers complete self-hosting and doesn't require an intermediary during operation...
Basically it leads to hubs forming where lightning nodes with large amounts of funds are better able to facilitate transactions, and also benefit from that due to transaction fees.
I actually agree with that about Bitcoin.
Web3 is generally done on EVM or cosmos chains, some of which are L2s (and some of which are loosely considered L2s). But most of them are still separate chains, so not L2s in the sense that the Lightning network is an L2. If you're looking at EVM chains, then L2s are certainly required to handle significant throughput, but the "lack of transparency" mentioned by GP isn't an issue with them.