As people have posted, W/Cda is obviously important. Reason, I (and many others) beat guys on lower W/kg since we hold a good position. However, running off the bike is just as important so you need to focus on training the entire thing.
To answer your question, if you want to win your AG in a large race, you are legit against guys/gals who may be basically pros that don’t take their pro cards. So its a real “who shows up” rather than how good you are; some people will just mop the floor and if you are in those larger races, its luck of the draw.
If you want to be competitive in your AG at most events, you basically need at minimum a 4.2 W/kg FTP imo. Larger races I think thats more in line with a 4.5W/kg. I know guys showing up to races at 5W/kg+. Monsters.
I think a very competitive W/kg is 4.5+. Anything north of that will land you in a top bike split, assuming you can hold position. That’s blind FTP only. My experience at least.