i had a lightning lab wallet back in 2019-2020. had some funds in it, not much, just about 8300 sats. apparently the wallet is no longer functional. despite being self custody, i lost access to my funds. it gives you a perspective about what does it mean really by self-custody.
Discussion
lesson - always be active if doing crypto
wallets changed a lot since 2009
Self custody bitcoin is easy, especially now with BIP39. Need extreme threats like a super quantum computer before it can break.
Lightning is a different matter. Need another 2-3 years before it'll be settled. Hence, look at it like a wallet for spending, like the one in your pocket now. You could very well lose your wallet anytime.