Before talking about "hogs" you should really benchmark and quantify what you mean. Rust apps are quite a bit larger than C++ apps in general, whether or not they are more efficient in terms of compute or runtime memory footprint is extremely variant. The reason to compare to C++ is because that's what an embedded chromium app is. The JS side is usually not that big of a deal compared to the rest of the browser engine that does the heavy lifting.
I was just wondering if Spotify (a CEA) contributed to that slowdown.
I've found that Rust is perfectly usable for writing GTK interfaces for simple apps. Those are much smaller, faster and feel better to use than a Chromium embedded app. It's also harder to port, inherently less capable and generally supported by a weaker ecosystem. It entirely depends on the application you need.