It's a 1-man operation so it may have not have been financially viable to architect the app as server-based.

- server-based : must invest a lot more money in server farms and extra disk storage, or pay high AWS cloud fees. E.g. if a million users do a blur or denoise filter, all that cpu processing has to happen on the servers, and massive disk space to hold the intermediate files, and extra bandwidth costs to send the changed bytes back to the client.

- client-based : just ship Javascript blobs to end users' web browsers because the blur/denoise/etc filters happen on the desktop.

Also, this type of pixel-editing software still needs a ton of client-side Javascript to behave like a Photoshop clone because users want to see interactive changes as they dynamically slide the blur/noise/etc settings. Round-tripping that with extra server latency is not a fluid UI experience.

We can't confidently replay the past and say that starting it as server-side app from the very beginning means he'd have the same $million in revenue today. Instead, the extra server costs and UI jankiness could have doomed the project.