Anything over 4 w/kg I’d say would be someone pretty fit.
Over 5 w/kg you can start mixing it with Elite racers and over 6 w/kg you will be looking at international level riders.
FTP is just a number and doesn’t really mean too much. When you start training by power and have a curve, from CP5 (5 minute power) to CP120 (2 hour power) or even CP180 (3 hour) thats when you can see your strengths & weaknesses.
Your (anyones) FTP will hit a ceiling and for many people its impossible to get above it, without very focused training.