2 hours later he's got a fully working piece of local software that does exactly what he wants, yet yours is not able to even sort dates correctly. Feel free to download it if you want to see for yourself, I didn't even do any UI tweaks as this was just a tool for him to use:
Linux - https://downloads.blazingbanana.com/whistle-subtitles/unstab...
Windows - https://downloads.blazingbanana.com/whistle-subtitles/unstab...
Mac - https://downloads.blazingbanana.com/whistle-subtitles/unstab...
How can there be such a massive gap in what can be produced?
What I was doing looks really nice and mostly works on the surface, but it is all about the corner cases where these bugs appear. In another day I was able to generate Frida script with LLM help that bypasses Dart certificate pinning/validation and proxies all the traffic by injecting the runtime binaries. With the latest Flutter/Dart version on Android when doing security analysis.
Sure an app can be built and spun up in an afternoon, but are you willing to spend another 6 months ironing out all those little bugs, tuning it a bit, testing, tweaking, testing etc.