Lightning is not private. It's been shown that transactions can be deanonymized. Not all that long ago the network was crushed by a single multisig transaction. Also lightning requires me to either trust a node operator (and pay them fees) or operate my own node and lock up funds on the lightning node in order to receive funds. With monero you have fast transactions, security, fungibility, privacy, and ease of use. It's also easier and cheaper to use. One thing we are lacking is integration into other services.