Personally, I hate Flutter and other cross-platform ideas for web development. I am biased in this, because I am a full stack dev who started on the web and I use React, Vue and TypeScript on a daily basis. Yes, those do get transpiled to plain JS, but not from a completely different language. Picking up Flutter to build a mobile app was super easy once I realized it is just another front-end app with the same concepts. I like to keep that separation. JS/TS for web, Flutter/Dart for mobile only. The web side of Flutter is still in a very poor state by what I keep hearing.