That's not the reality. The kernel network stack does a lot of things that for some applications are not needed, so DPDK is used for those cases when they need

That's not the reality. The kernel network stack does a lot of things that for some applications are not needed, so DPDK is used for those cases when they need very high performance. For example, packet capture, routing, packet generation... I don't think I've seen anyone rewriting what the kernel does precisely because when you use DPDK you don't want to do what the kernel does.