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.
No reason for off-chain unless the high demand for on-chain transactions fill the mempool and/or block space to its full capacity. Ethereum has built off-chain layers, which proves that on-chain, nothing can defy the limitations of hardware and bandwidth. Plus DYOR on Solana's congestion. The assumptions flawed and laughable. Their developers are not telling their users/community the actual truth on how their design will not work. A fee market must exist to avoid transaction failure.