It is good for stuff like craigslist or splitting checks.

The following scam works with craigslist + paypal, but not zelle:

You sell me an expensive item. I paypal you the money. You check your account and see that the money landed. I walk away with the item and immediately reverse the paypal transaction.

Note that the “I sell you a stolen/broken thing that will definitely be traced to you” scam works on both paypal and zelle, since the time to discovery of the scam is long enough to pull the money out of PayPal.

I’m not sure how hard it is to set up a burner zelle account and use it for untraceable crimes. It’s apparently easy to do that with paypal.

But, to your point, yes, they’re both pretty terrible services from a consumer protection standpoint.