Or did I simply misunderstand, and you're trying to say is Lightning "can be built" on top of other chains, not only Bitcoin?
That's what I meant, even though there is little to no reason to do it elsewhere.
Imagine a trader who wants to move their fund immediately to the exchange and sell it.
Actually, that's the most useful part of LN, in my opinion. Instant transactions are awesome, but that's rarely the reason I'm paying or receiving in lightning. The greatest property is that you can make nearly infinite transactions by creating just two UTXOs (for each channel). You can't DCA on-chain, with self-custody. You'll lose a lot in transaction fees, especially if you use a decentralized exchange like Bisq which requires at least 4 on-chain transactions for every trade.
Robosats is the best non-KYC, lightning exchange for that particular purpose.