Plenty of L2 solutions already exist and can be used with Ethereum already. If your single comparison point is the existing banking and credit card payment networks, you can take a look at e.g, Raiden which is already deployed on mainnet and can scale with the number of the nodes participating in the network. Hundreds of thousands of payment transactions per second are already possible.
The main issue is that most of them still are very complex to get fully operational, there is no big consensus among users on "what-to-use-when" and they all require a non-insignificant cost to setup in terms of all the contract transactions needed to get in and out of the chain.
There is no reason to doubt that they be more mature along with ETH2 and that that L1-L2 will complement each other nicely.
I could take a look at e.g, anything... but when you add a caveat of participation, scaling to infinity is inherently possible. If we all chose to do something, we could all do it.
The problem comes with attracting such participation, which isn't warranted without that very participation having already been established.
If I understand you, you are saying that Ethereum is not important because people are not valuing as highly as BTC, so the transaction throughput is irrelevant and L2 is not going to be needed.
This is akin to saying that it doesn't matter that e.g Brazil has a more advanced banking retail industry compared to the arcane networks from the US because the Brazilian economy is not as big as the US.
This is silly, because not only the two economies can co-exist, there is no technical aspects that stops other chains to adopt PoS as well it also ignores that the value can be migrated from one chain to another.
Increasing throughput in Ethereum would make everything more valuable. Just as an example, people can get their BTC and transform wrap them to use in the ethereum chain. With ETH2, it will be cheaper to wrap BTC and cheaper to use it in transactions.Its utility will be increased.
The main issue is that most of them still are very complex to get fully operational, there is no big consensus among users on "what-to-use-when" and they all require a non-insignificant cost to setup in terms of all the contract transactions needed to get in and out of the chain.
There is no reason to doubt that they be more mature along with ETH2 and that that L1-L2 will complement each other nicely.