lsof is available on Mac's by default, ss is not, so significantly smaller depends on your platform I guess. I believe ss is not available for Mac at all, where as lsof is widely available.
In this case the AI answer might be somewhat better for Mac. On Linux I have more often manually installed lsof than ss (iproute2). Maybe Mac provides the similar command netstat which is yet another tool to check ports
netstat -nltp | grep -P ':8000\b'
¹ How to get current users name. Maybe whoami or id -un or logname or echo $USER or who -m or who am i (learnt this last one just today; apparently works with any combination of two arguments after 'who')
netstat -anv
I'm sure there is a few ways to skin the cat, but on Mac the most equivalent to the ss command would probably be:
sudo lsof -iTCP:8000 -sTCP:LISTEN -n -P