Interestingly, that's exactly what is going on internally at the moment with Dart code, as we migrate the Google ecosystem to sound null safety, which was introduced in Dart 2 and will be the only mode in Dart 3. Adding a feature like sound null safety to a codebase the size of Google's is a large undertaking. It also brings a ton of benefit, both to the language itself and code that has migrated, since we can now provide guarantees around nullability that are not available in most other languages.

But all the tooling we built for that multi-million LOC migration is open source, and available to everyone as part of the core SDK (https://dart.dev/null-safety/migration-guide#migration-tool). It's sophisticated, migrates much code automatically, and provides a visual editor to help make decisions about other code. That should be evidence at least that we care about migration.

Every ecosystem goes through migrations at some point (Objective-C to Swift, Java to Kotlin, Win32 to UWP, etc.) Flutter isn't immune to that risk, but I don't think it's particular to Flutter either.