BTC already has a few L2 projects built on top of it. One of them is Stacks and it's quickly gaining traction. It aims to bring the best of both worlds right into the Bitcoin blockchain. You will get the smart contract capabilities of ETH with all of the added security benefits of Bitcoin. All of the buzz is on Solana right now. But that won't last for long. Especially as people move on to the next big thing in crypto.
Stacks could get hyped as it rises all the way to glory. This will leave ETH dusting in the corner. I agree with you that core Ethereum developers need to do something. They need to increase on-chain transaction capacity if they want to help prevent ETH from losing market share. The much-awaited Danksharding protocol upgrade aims to fix this.
With an increase in TVL, ETH could solidify its position on the market. Otherwise, rivals like Solana, TON, and Stacks will "eat its cake". No matter how far ETH goes, there's no denying BTC will stay at the top forever. "You can't beat the real thing".

Just because something is being done, doesn't mean it is needed or liked or even benefits. I never liked L2 projects even in other stuff, let alone be a good thing for Bitcoin itself. I didn't like projects that were L2 for ETH neither, just because gas fee was high in ETH doesn't mean that it would stay high, meaning that one day ETH gas fee would drop (which it did) and all those L2 projects would become useless (which they are now).
So while people do see L2 as an alternative, I always found them temporary solutions and not going to stay high for long. I believe that we are going to get all of these things out of our market and crypto world eventually, so investing into them, or even simply caring about them, will not benefit us.