Possibly but not guaranteed.
For desktop apps UI quality and rendering speed is paramount. There's a lot of stuff buried inside Chrome that makes graphics fast, for example, deep integration with every operating systems compositing engine, hardware accelerated video playback that is integrated with the rendering engine, optimized font rendering... a lot of stuff.
If your Rust UI library is as advanced and well optimized as Blink, then yes, maybe. But that's pretty unlikely given the amount of work that goes into the Chrome graphics stack. You absolutely can beat Chrome in theory, by avoiding the overhead of the sandbox and using hardware features that the web doesn't expose. But if you just implement a regular ordinary UI toolkit with Rust, it's not necessarily going to be faster from the end user's perspective (they rarely care about things like disk space unless they're on a Windows roaming account and Electron installed itself there).
Having worked on a graphical application in rust for a (albeit not a complex one) computers today are fast.. latencies top out at 3 ms with cpu based rendering in an application with just a few rendering optimizations.
The fact that you just draw on the screen instead of doing whatever html parsing / DOM/IR is probably doing it? And doing rendering on the gpu means extra delay in the processing moving from cpu to gpu and being a frame behind because of vsync.
Can you clarify this? Seems to me that no matter how you render your UI, it has to go to the GPU framebuffer at some point.
For any non-trivial case where I can enable GPU acceleration for an app, it's been anywhere from equivalent to much more responsive.
What apps have you experienced delays with by enabling GPU acceleration?
Where it really shows up is stuff like power usage and reliably hitting framerates even on slow machines with big hi-res monitors attached.
Point of information: I believe this project uses Tauri, which actually does use web technology and even JavaScript for rendering, it just does it with the native web renderer of the platform so you're not dragging around a superfluous extra copy of Chrome in RAM for each and every individual app:
"Write your frontend in JavaScript, application logic in Rust, and integrate deep into the system with Swift and Kotlin."
"Bring your existing web stack to Tauri or start that new dream project. Tauri supports any frontend framework so you don’t need to change your stack."
"By using the OS’s native web renderer, the size of a Tauri app can be little as 600KB."
So you write your frontend with familiar web technology and your backend in Rust, although it's all running in one executable.
I am curious if it would be all that much worse if your backend was also JavaScript, let's say in Node.js, but it certainly depends on what that back end is doing.