L-BTC, as I understand it, you deposit bitcoin into a federated entity, of which blockstream is one amongst many and that list is continuously growing. All of these companies would have to disappear for this network to stop functioning. L-BTC acts exactly like bitcoin, but with lower fees and faster blocks.

Lightning still requires that you deposit your bitcoin with some entity, whether that be an LSP or otherwise, a trusted third party is still in play. And there are many different implementations of lightning, which can cause issues.

I use all three .. lightning for payments, L-BTC for utxo management, and BTC for cold storage ..