Besides your title being a bite, I totally disagree with the part "It’s great when time to market is the most important factor, however it is not so great when you need a long term, bulletproof solution."
We run the Flutter app for more than a year in production (I wrote about it here: https://medium.com/mews-devs/1-year-in-production-with-flutter-lessons-learned-5de86723c5df ), constantly maintaining it and adding new features, and I'm completely satisfied with our choice to use it for a long term solution.
Regarding the bad things you've mentioned:
- "it doesn’t have its own, dedicated IDE" – do we really need another one "dedicated" IDE? Both Android Studio / Idea and VS Code provide a decent support for Flutter. Could it be better? Sure. But (at least, for me) the experience is way ahead of Xcode one.
- "Dart can be a dynamic typed language, which can be very dangerous!" – every feature can be dangerous. Dynamic feature may be not needed in 95% of the time – so we just don't use them. But in remaining 5% they can make the solution much simpler.
- "you can omit return type, and IDE will not know about your type" – can be fixed by proper static analyzer configuration.
- "Troublesome code generation" – what's so troublesome about it?
- "Sometimes you can observe UI “Janks” — can be because of your code or engine bug" – how is it specific to Flutter? Bugs can be everywhere.
- "You have to be careful when it comes to performance" – shouldn't you be careful when it comes to performance in native app?
- "Some bugs are not fixed for a long time" – some bugs in native Android are fixed... never?
- "You have to use community driven solutions" – do you normally write a big native app without using 3rd party community driven solutions?
- "Lack of mature JSON serialization" – what do you call a mature one? We use json_serializable from the beginning of the project and didn't have any problems with it.
- "We cannot treat Google as a guarantee of long term support" – should we be afraid of native Android as well in that case?
Flutter is not perfect, sure. It won't suit any use case. But it's not just about reducing TTM by compromising on performance/maintainability/stability. You can build a high quality production app and make it faster and easier.
