Till now I've been dealing with the backend, so my knowledge of the frondend languages/tools is limited. For my next project I want to code the frontend too (full stack?). I've been reading about Flutter, which seems promising for developing iOS and Android apps and maybe even desktop ones.<p>For Web, I thought AngularDart would be appropriate for code sharing between all apps. But by looking at their github, I'm not sure if it's in active development. On the other hand, Angular looks pretty good for web. But code sharing would be a problem with Flutter. But will be easier with NativeScript.<p>So, I'm not sure if I should focus on Dart ecosystem or JS/TS ecosystem. Please, share your experience if you been through this process. Thank you!
I have had the same mindset as you. I got a project to create a website including the backend. At that time I started learning Flutter and Flutter Web also got released. But Flutter is easier to learn and faster to develop when comparing to other frameworks like React Native and all. Since I am familiar with Java and C# Dart was easy for me to learn. So I started to develop the website in Flutter Web. I finished most of the things within two weeks including the backend. But there is a problem in the performance when scrolling. It's a known issue. Same happening when browsing the site in the mobile browser. So I had to change the Framework from Flutter to Angular Dart. I started learning Angular TS few years ago by watching Udemy tutorials. But unfortunately I did not understand anything. But I learned Angular Dart myself by looking at the Documentation. Now I am good with the Angular Dart.
As you have said in the post, code sharing will be a problem but only the code that you could share is Business Logic. You have to re create the UI for each Framework. It's not a big deal.