I think there is still lots of confusion around fake zaps.

I trust my node to not fake zaps. That gives me strong guarantees if I want to use my node’s zaps for spam filtering and ranking things based on zaps to my posts.

Zaps aren’t as useful if you are trying to rank things from other untrusted zappers, aka zaps from other people. If you suspect a fake zapper, then you should either block that persons zapper or the person themselves.

Since there is no general mechanism for validating if a lightning invoice is paid, the best thing to do is use zaps in ways that are safe and reliable to use them. Ranking stuff from your own zapper or zappers you trust is fine, in general from other people outside your web of trust, it is not.

If you are using a custodial service that sends zaps you have to trust they aren’t doing something weird, but that is a less common scenario and you can switch wallet providers if they do weird stuff like that.