I have had the exact same experience. I’m not a big fan of React or React Native, but I can see that it does increase code reuse; but...
As you say, platform-specific glitches will always crop up so you’ll always need a bit of native work. If you’ve thinned out native development team this can make things hard. Instead of a team of 5 or 10 native developers working on bread-and-butter UI stuff, you only have enough work for 1 or 2, but it’s all grungy stuff like talking to low-level frameworks and working around platform bugs (or React Native bugs, of which there are plenty). That’s not a recipe for clean and maintainable code.
A related issue is that React and React Native aren’t 100% compatible. You can’t just move existing React code directly over as you might elect. It is possible to write code that works on both, but it isn’t trivial.
QA definitely needs to be done separately on each platform.
As you say, platform-specific glitches will always crop up so you’ll always need a bit of native work. If you’ve thinned out native development team this can make things hard. Instead of a team of 5 or 10 native developers working on bread-and-butter UI stuff, you only have enough work for 1 or 2, but it’s all grungy stuff like talking to low-level frameworks and working around platform bugs (or React Native bugs, of which there are plenty). That’s not a recipe for clean and maintainable code.
A related issue is that React and React Native aren’t 100% compatible. You can’t just move existing React code directly over as you might elect. It is possible to write code that works on both, but it isn’t trivial.
QA definitely needs to be done separately on each platform.