(I'm on the Flutter team.) IPC is "inter-process communication". This message passing is same-process. We haven't yet proved that it's sufficiently performant

(I'm on the Flutter team.) IPC is "inter-process communication". This message passing is same-process. We haven't yet proved that it's sufficiently performant for extremely latency-sensitive work, and we currently copy the bytes for the messages when switching so it's not very suitable for high-bandwidth work like video where you're sharing the bytes between Dart and Java.