Actually, I thought the same about flutter. As it seem to be a huge effort to maintain and further develop it. Even Dart seems to be only used for flutter development. The technology behind flutter is complex, similar to react native. If Google or Facebook would stop support for these tools, I think, it would be highly challenging for the open source community alone to maintain it. Facebook uses RN as part of their core products. However, I don't see the incentive for Google to maintain Flutter...