(EDIT: though the only real confirmation of this being done that I have is, Samsung's "Camera Assistant" addon has an option to enable "2x zoom" as separate button, and the description there states explicitly it's a synthetic zoom made from combining the main and telephoto camera.)

(EDIT2: come to think of it, for almost any regular mode, if I use my fingers to block two of the three cameras, the image is unchanged, which empirically proves at least Samsung is not doing this - which again makes me wonder, why not? It's an obvious thing to do.)

On that note, I don't understand why there's no widespread, genai-free apps for "super resolution" aka. take a video (or a burst photo shot) of a stationary thing and use it to reconstruct a single photo with much higher detail level.

For videos I can imagine the reason would be that video compression is literally doing the inverse of that (i.e. the information you'd need to reconstruct a higher-resolution image is exactly the one that the compressor throws away for 90% of the frames), so the algorithm and compressor would cancel out. But that doesn't explain why this doesn't seem to exist for burst photos.

Of course the extra detail in the middle is nicer, but won't the edge of the "detail rectangle" be extremely obvious and distracting? Like when you zoom into satellite view on Maps and it's clear that there's a blurry area and a sharp area?

I don't understand why you'd ever want these two things combined into a single image. I can understand why you'd want to snap photos with both lenses simultaneously as save them as separate photos, but I don't understand why you'd combine them.

Subscriptions are charged because the developer needs to maintain the upkeep and cost of running the service, but that's not applicable here. It's capable of taking a million photographs fully offline, without any reliance on an online service.

Essentially you're saying your product is so superb that people should pay you indefinitely for the privilege of using it. Even though it costs you nothing to maintain, you somehow need people to perpetually pay you for a local, offline algorithm that you wrote one time. How gross, that's the definition of pointless greed.

Shame on you, honestly. This is exactly what's wrong with modern software nowadays. Just like Adobe and all these other companies, taking advantage of people to milk them dry forever. You'll lease a product, you won't have the right to own anything, and you'll be happy about it.