All of those communication modes are actually useful. Seqpacket works especially well. You can build whatever high level facilities you want on top of them: I h

All of those communication modes are actually useful. Seqpacket works especially well. You can build whatever high level facilities you want on top of them: I have several times. Ease of use at the raw system call level is not relevant: application developers shouldn't be working at that level anyway. If you want object IPC with a reply and receive operation, you can use Android's binder, which is already in mainline.