SPAs to Flutter is a much smaller step conceptually than native to Web. Most of the world is using a Blink-based browser of some sort already. Updates are pushed aggressively.

> What has flutter to offer that a regular webapp lacks?

Google branding, novelty, more sane dev UX. I'm not saying those are good reasons to choose it, I'm just extrapolating from how the industry works.

Let's be honest: end users basically just put up with whatever devs release at this point. It doesn't matter if the end product murders battery life, doesn't fit the target platform, and steals their data. It's not like switching to some less-than-web-native framework is somehow a bridge too far for end users.

Your last point made me think: for all the flak the gamer demographic gets for being over entitled and toxic, they seem to actually ultimately end up with nice things like programs that run at a performance you'd expect from a modern computer and don't swamp you with creepily-targeted ads

The fact that it (the same code base with minor changes) runs on desktop and mobile platforms?

Great point. It is striking to me how similar many of the modern languages are for various platforms (thinking of Rust, Kotlin, and Swift here), but it is still quite difficult to share business logic among web, Android, and iOS devices because of language differences.

If Dart/Flutter is good enough for all of those platforms, that is quite the value proposition.

Resume lines.

This is correct, I am afraid.