What it can do, and Ubiquity already had this as a separate product, is act as a fallback for you regular internet connection.

You can do the same with Mikrotik and a ton of configuration, the pitch with Unify is that it "just works".

"It just works" with Teltonika and Glinet as well. In most of the openwrt based routers multi-wan is already enabled. It is also very easy to do with TP-Link Omada (just enable a checkbox).

So, implying that Unifi is the only company that does this in an easy way is misleading marketing.

Comparing against Mikrotik is a very low bar.