Charging EU citizens more than French citizens would be illegal discrimination under EU law. (It might be legal to charge local Parisians less.)
For example see https://brusselssignal.eu/2024/12/ec-demands-end-to-portugal...
For example see https://brusselssignal.eu/2024/12/ec-demands-end-to-portugal...
Some time ago Germans tried to tax foreign drivers on their roads, so they introduced toll, nominally for all, but also lowered the same amount another car-related tax that was paid only by Germans. EU bodies saw through the scheme just fine and now they're on hook for returning the toll money to anyone still keeping the invoice/receipt.
Of course this is against the interest of other countries, which is why they prevented that, but it wasn't unfair or discrimination.