If I'm understanding ublk and your question correctly, then yes, there are a lot of kernel-bypass networking options out there, such as openonload, dpdk, mellanox (though they seem to have been absorbed into nvidia). You'll likely need a special/particular network card, an external kernel module, and at least an LD_PRELOAD to use them though.
Yes, and also just to note, zero-copy and kernel-bypass are independent. Traditional Berkeley socket syscalls are copy+kernel, io_uring has/will have zerocopy+kernel, openonload provides both APIs for copy+kernelbypass and zerocopy+kernelbypass.
XDP is a lot of stuff, but I think I have someone around using af_xdp to bypass the kernel network stack and for some (and the filtering and decision of which streams, is done through some ebpf iirc) packets deliver them directly into userland buffer-queues? DPDK also has an AF_XDP backend to bridge your classical DPDK app and AF_XDP sockets.