[millstone]

The native apps you mention have heavy customization because they are meeting advanced professional needs. But these apps still participate in the platform's UI conventions. Menus, windows, etc. work like Mac or Windows users expect.

Electron apps are also heavily customized, but ignore platform UI conventions. The buttons may have lovely drop shadows, but basic interactions (menus, undo, drag and drop...) are routinely broken or work in some discordant, unfamiliar way. This isn't meeting professional needs; it's that web tech sucks for building actual apps.

And even if web tech improved, there's still the cultural bias towards re-invention and churn. Web dev will always cons up a button from a div and an onClick handler, no matter what the framework provides. There's no mechanism to get web apps onto a shared UI platform because the gravity of the web is dispersive.