Monero's blocks store public historical data that proves random strangers around the world transacted money following the rules and no one trusts each other but still can't cheat on each other. This sets a history of all-look-equal transactions that make up the current state of balances and histories that only key holders know the details, like what the hidden amounts are. A LN payment on the other hand is routed A -> B -> C with all amounts being visible from sender until it reaches the destination, now which privacy is better 1) all-look-equal txs with hidden amounts, or 2) plain text, amount visible, routed payments where A -> B -> C, but B can be a FED making public profiles?
Routing nodes do not know what amount is being transmitted. They only know the amount *they've* been asked to forward, they have no idea if that's the full amount. I don't know what persuaded monero guys that publishing their transactions is good for their privacy but it's an obvious problem that bitcoin fixes.
Monero guys believe in trusting no one, so with XMR I can only send a tx that 1) no one can stop from being mined 2) no one else knows the details. On LN nothing stops colluding routing nodes from creating a graph/profile of LN users and their activities and knowing the full amount transmitted, and nothing stops routing LN nodes from simply censoring certain senders/receivers on their route. Not good, we like privacy and censorship resistance above all, even if txs are "published", or permanent