This is absolutely horrible and I hope I never have to use it on the web - right click doesn't work, my plugins don't work, I can't even open DevTools and when I manage (before the app has loaded), it's just a <canvas> element in the page. I know a lot of people put work into this and something is probably better than nothing, but actually no, I think such solutions are disgusting.
If you're gonna claim cross platform, don't just stoop down to the lowest common denominator and write a bunch of pixels to the screen, use the damn system UI solutions, or in the case of web apps - HTML, CSS and JS/WASM. I already take an issue with Electron (Lazarus lcl did things right, in contrast) but realize that it yields a lot of utility, yet these canvas based approaches for web apps feel like a step too far.
Yet obviously nobody can admit that they can't do the heavy lifting needed to support multiple different target platforms for the same widgets in a way that respects the corresponding platforms, while also still wanting to ship something. In this case, I think nothing is better than something, if that something is so bad.