The solutions proposed are not true second-layer solutions, but rather a central network which uses zero-knowledge proofs, which instead of being stored in the main Ethereum chain, are stored in separate data chains such as Celestia. Therefore, solutions such as Validiums are separate altcoins and not a second layer.
I see that the trend now is in L2 (Not AI, DeFi, IEO,...etc,) where some chains will store data on the mainnet and claim that it is a second network, which means more spam for the mainnet, which gives them a strong reason to use them.
In short, there are a lot of altcoins that are happy for Bitcoin and Ethereum fees to be high, otherwise the value of these altcoins will decline sharply.