I can't shake the feeling that this ship has sailed and only a few got to get on it while it happened.

And this comes from someone who started with Flash, built actual video editing apps with it, and for the last 25 years build application with "it's not a web app, it's a desktop app that lives in a browser" attitude [1].

Even with Flash we often used hybrid approach where you had two builds from same codebase - a lite version running in the browser and an optional desktop app (AIR) with full functionality. ShareObjects and LocalConnection made this approach extremely feasible as both instances were aware of each other and you could move data and objects between them in real time.

The premise is great, but it was never fully realized - sure you have few outliers like Figma, but building a real "desktop app" in a browser comes with a lot of quirks, and the resulting UX is just terrible in most cases.

[1] just to be clear, there's a huge difference between web page and web app ;D