An air operator's certificate (AOC) is the approval granted from a national aviation authority to an aircraft operator to allow it to use aircraft for commercial purposes
You either have and AOC or not. If you don't, you must not operate anything commercially. If CAAs around the world wanted to (really) re-enforce the concept, all they should do is to spot-check aircraft documentation such as asking for the AOC.
AOC = commercial permit. ATC FPLs filed as G with pax? Are they all admin flights (non-revenue)? How many G coded flights are flying around with revenue involved? There isn't really a proper 91K outside the US to my knowledge. I accept corrections.
The French and Italians are on the right track, but they should also expedite the proceedings and above all be available to approve requests during weekends and holidays for short-notice landing permits (for non-EU27 countries).
We all need to make money fairly/squarely, CAAs, Airports, FBOs, Operators, Chaterer Brokers, etc..