Lightning is a layer 2 that is created on a PoW and performed on a PoW, I wouldn’t classify it as either a PoS or a PoW. The analogy I would use is more of an attached payment system that is built on top of the existing Bitcoin network, similar to an aggregator. But you’re right, it is great.
Discussion
You literally have to a proof your stake when creating a payment channel. It's the only viable PoS out there.
It’s not a consensus method. It’s just providing liquidity. Settlement is still happening on BTC L1.