Earlier quoted context omitted.
It doesn't have the scrutiny regarding cryptography and implementation that Signal has had.
They claim to have secure end-to-end encryption. In fact, I would say using wire.com is better than Signal because Signal does not make any guarantee of anonymity. With the wire desktop app you can take steps to anonymize your connection to their server, although on a mobile device it's probably roughly equivalent to Signal. Also, here is a handy chart that compares the differences between these two services (and oth…
They have broken voice encryption, and leak enough data to reconstruct the audio of your calls. They leak tons of plaintext directly back to themselves, like GIF searches, and rolled their own messaging crypto that experts say is broken.
They have been caught lying about what kind of encryption they provide, they lied about being open source for years, they lied about being based in switzerland. From what I can tell, the only people promoting Wire after all that are usually on Wire's marketing team.