Nothing necessarily at the tech level. They're more capable than Appimages or flatpaks to the point that you can use it to build a reproducible system hardened against tampering or defective updates.

The downside is that it's controlled entirely by canonical, has limited abilities (if any?) for hosting storefronts/packages outside of their ecosystem, and said ecosystem is insecure and has already allowed multiple waves of malicious apps to reach end users because of poor moderation of listings masquerading as legitimate versions.

Canonical has also been increasingly hostile to flatpaks - removing it from Ubuntu and derivatives by default to push users towards snap.

The whole loopfs thing is just an annoyance, but the aggressive posturing by canonical as well as the closed nature of the storefront that has led to malicious attacks on end users is enough to give it more than a few haters.