Fog lamps are more and more common, but still not standard on cars sold in France. Years ago on cars equipped with fog lamps they would activate only with the low beam headlights, and would automatically deactivate if you switched to high beams. Now you can keep them on with high beams too, but they will not activate with running lights only.
Concerning running lights, I’m not even sure what the current regulations are. I believe it is still allowed to drive only with running lights in a lighted area, and I must say this is what I do most of the time. Assuming the lighting is good enough, and the weather is cooperating, running lights are in my opinion sufficient to identify other moving cars (otherwise -maybe- you have no business driving at night).
A while ago (maybe 15 or 20 years?) the authorities started a trial period, where they required cars to drive with headlights on (low beams) at all times (as in Holland, Slovenia, and a few other countries). But that didn’t stick, I don’t know why.
Beginning of the nineties, we had to switch from yellow headlights to white. Although I drove several older cars with their original yellow lights until last year (when I sold both cars), not once was I stopped, let alone ticketed. And I don’t see how white lights make for better lighting, but they certainly are more blinding in cross traffic.
I don’t dislike being French, but I have a hard time understanding some of the idiosyncrasies that come with this nationality! Custom, history, tradition, all this I understand and enjoy (not just in France), so-called Gallic flair (!) maybe sometimes or in some specific areas, but there is a certain type of Mediterranean insouciance (in a country where the majority is hardly Mediterranean), an absence of focus on results, and a fierce desire to do things in our own way, and to resist following rules, or work together, which I find infuriating.
All of which took me very far from fog lights on French-registered German Pagodas...