I'm curious about the benchmark. In my own for another network IPC library (https://GitHub.com/ossia/libossia) Unix sockets were consistently faster than the alternatives when sending the same payloads.

the linux results are for a vm running on macos. not sure how useful that is. i certainly wouldn't draw any wider conclusions from them without trying to reproduce yourself. pretty sure they will be very different on bare metal.

i couldn't resist reproducing on bare metal linux (8th gen core i5, ubuntu 22.04):

  cargo run --release -- -n 1000000 --method unixstream
  cargo run --release -- -n 1000000 --method tcp

~9μs/op for unixstream, ~14μs/op for TCP.

unixstream utilizes two cores at ~78% each core, tcp only utilizes ~58% of each core. so there is also something wrong in the benchmarks where blocking is happening and cores are not being fully utilized.