Flutter is still open source with a stronger community than any of its competitors. I think it will be around for a long while. For some reason, it's especially popular in Asia, particularly India and China. There are already entire modules being developed just for Flutter in China, so I wouldn't put it too soon in killedbygoogle.

The iOS issue is a minimal issue with the new Impeller API (not sure if you're updated on that). There is still a bit of jank, but between putting out an MVP vs another month for a native app, I'd say go with Flutter for the MVP. Then switch to native if your app takes off.