There are two new app only banks here in Switzerland and they both use a cross platform framework. One for sure ionic. On Android these apps are absolute garbage. They are slow to start, slow interaction and slow animation. One of these apps has a main.js in it that has over 200k lines of crap with hundreds of lines of if (ios) and if (android). All the iOS styles are packed in the Android apk which is just stupid.
If these banks want to compete with revolut or transferwise they need to provide an app that's isn't garbage.
My local bank has a native app as far as I can tell and it regularly takes over 10 seconds to get past the login page. My credit card (Discover) app somehow won an award for best UX in the industry and still takes over 5 seconds to log in (both of these are with Face ID by the way).
Contrast this to Robinhood, which jumps from cold boot to main screen in about a second.
The problem is not the frameworks, it is poor development practices. Until the big guys learn that outsourcing critical software is a stupid idea, the next generation cool kid apps will continue to eat at their customer base (until they become relevant enough to be bought out by the big guys, and the cycle repeats).
There is a difference between mission-critical and critical for the business.
For an entity like Snapchat, it is the business. It'd be stupid for them to even think of trying to cut corners to save a few bucks by maybe sharing some code.
Not saying you are wrong at all - building something with highly complex interactions, real time image manipulation etc. such as Snapchat would likely require dropping down to native code for a good part of it - but “maybe sharing some code” isn’t really fair - in my experience, React Native allows you to share the vast majority of code (aside from any native bits, of course).
We’ve built a pretty complex and highly visual music learning app for iOS and Android recently, and thanks to the combination of React Native, Unity and JUCE (C++ audio framework), pretty much all the code is shared. Seeing it run on Android with no big changes needed (aside from audio stuff, which is a challenge on Android in general) for the first time was pretty impressive. Even given unlimited resources, I’m not sure I’d choose to go down the 2 native apps route - automatic feature parity across platforms is a pretty killer feature.
If you were building something like Snapchat where I guess things like app startup time and performance on budget devices are important, I can see why you’d choose to though.
