Well, the non-earthed variety are pretty old at this stage and new installations require earthed sockets.
As far as I'm aware the same situation applies in other parts of Europe and in the USA too.
Also, in general French installations are fully RCD protected. So the likelihood of getting a shock, even from a non-earthed outlet is quite low.
A modern French installation is as good as you'll get anywhere in the world.
Bare in mind that a lot of British people's experiences of France are based on staying in "Gites" which tend to be old converted barns, many of which were converted in the 1950s and still retain a certain 1950s electrical charm!
These old houses will often only have earthed sockets in the kitchen and bathroom!
Don't forget too that France took a good few years to recover from the ravages of WWII, so it's not unusual to see all sorts of ingenious work-arounds on properties of this age.
I once saw a French house in which at least half the walls had been built entirely from roofing tiles, overlapped horizontally and cemented together! Oh, and the wiring was euqally as, er, interesting.......
I'm sure if you poked around some 1950s installations in the UK they'd be equally dodgy! Modern sockets could have been retrofitted to ancient wiring systems.
At least in France if you see ancient non-grounded sockets, you know the property needs attention!