I want to learn cross-platform application frameworks like React Native, Flutter, Xamarin, or Ionic, and I'm a web developer. I can learn other programming languages as well. But I'm confused about what to learn, which framework is best, and which framework will last long as the application grows further into complexity.
Flutter is the best one. If you are a new comer in mobile app development, choose Flutter.
But if you have strong experience in JavaScript and you have a lot of JS websites that you want to develop into mobile apps, choose React Native.
Ionic also has its strong points such as a lot of prebuilt components for different platforms and minimal dev environment requirement (you only need a browser).
I already have a strong hold on JS. I think React Native is good
React Native has a very rich ecosystem and if you're already a web developer, the skills that you already possess will transfer over very well. React is the second most popular web framework according to Stack Overlow's 2022 Developer Survey. No one framework is the 'best' as they all serve different purposes and have different use cases. If you're looking to pick up something popular, I would recommend React Native.