You're comparing on-chain vs L2. Lightning is built on a transparent blockchain so still leaks data even if you do everything perfect.

Also, since most lightning users are custodial, they might be private to the general public, but they are naively surveillable by the custodians and any government that forces them to record that information and could do it covertly with a gag order. Basically the same trade-off as a VPN. You're just shifting who can invade your privacy for most Lightning users.

When Monero upgrades to FCMP I'm curious would you use it? Also would you use Monero when it has an L2? Since both things would alleviate your problems with it in regards to private transactions.