My French mobiles regularly get "ping" calls, the ones that last for a single ring to trick people into calling back. They all have Tunisian country codes, and since I know no-one in Tunisia I now just block all calls with that prefix.
My French landline gets 1-2 unwanted calls a day, and if I don't recognise them (which is true for almost all) I let them go to voicemail. It's rare to get a message left, except the occasional "You have a new message, press *" scams.
Both numbers are registered with Bloctel (the French TPS equivalent), which seems to do nothing much.
That said, I did recently get a message left from the De Vere Group of financial scammers. They'd obviously become fed up with me ignoring their calls to my office (admin instructed not to put them through) and refusing LinkedIn invitations, so some bright spark at DVG had found my home phone number, and left a message complete with her name. I took great delight in formally lodging a complaint with Bloctel for that one, although I have no idea whether it did anything. Pity it was just pre-GDPR.