Good share, like you I also started native iOS development during 2010. But now I like Flutter more than native iOS development. For me, the main reason, Apple’s app review policy. Sometimes they reject apps for weird reason. As an Indie app developer, if I invest much time to develop a native iOS app and Apple rejects it hurts. At least, using Flutter I can make app that also runs in Play store. And google play store, doesn’t have weird policy like apple.
For example, I developed a cross platform app using Flutter, https://github.com/mahmudahsan/flutter_todos. It has in the play store, but Apple rejects to approve this app, they said it has minimum functionality. so you can not follow the MVP policy to develop app and expects Apple will approve.
This is just one example, there are many more in my experience.