The limiting process for its privacy is the conversion liquidity to/from BTC. https://youtu.be/va1pnsCnqHI?si=qMzZz6-COrUnJSMx
And Bitcoin has zero privacy. It is a public ledger. All connections and amounts are completely visible to anyone on the planet.
lightning is not.
Not the way 95%+ of users use it. Custodial wallets and LSPs can see everything they do.