You're implying that application written in Rust would not have no size, memory and security issues. That is of course not true.
Though I do think it’s unrealistic that the legions of JavaScript devs are going to learn rust to make simple desktop apps because it doesn’t really have a reputation of being an easy language to learn.
No, it won't be. You gotta weigh years if not decades of Node/JS experience vs 0 years of Rust experience of the average dev. Development time will be far shorter too.
A big enough application will dwarf Chromium's memory usage with its own, but for smaller apps, the cost of running your own Chromium instance will dominate your app's memory overhead.
a) Compiled JS apps generally have to include a whole Javascript engine, which makes them significantly larger b) Rust is designed for shipping small static binaries, whereas Node is not; node.exe by itself is tens of megabytes, and you can only make it smaller by compiling it yourself from source. Deno has compiling static binaries as an explicit feature so it may fare better in the long run, but it's still limited by a)
As an example: I just tested on MacOS and a hello world program compiled with `rustc` is 378KB, whereas one built with `deno compile` is 74MB.