> (and there doesn't seem to be a way to resolve usernames, as `netstat -e` does)

Challenge accepted:

  ss -e | grep uid | gawk 'match($0,/uid:([0-9]+)/,u) {printf "%s user:",$0;system("getent passwd "u[1]" | cut -d: -f1");}'

Not your point, I know, but it was fun.