I am confused about this "airways" business.
"Airways" are just lines on the map.
What matters to whether a pilot with particular papers can fly somewhere is the
airspace classification e.g. Class A,D,G etc.
France has a lot of Class E between FL065 (generally) and FL115. FL120-FL195 is Class D, in which enroute VFR is banned (a breach of ICAO but hey they are French) and FL200+ is Class A, generally.
It so happens that that airspace has routes drawn in it, which UK PPLs call "airways", but really they are just suggested routes. These routes are common to the Class E (say FL065-115) and to the Class D above that (say FL120-195).
So a plain PPL can fly there VFR FL065-115, and an IR holder can fly the same routes FL065-FL195.
The IR holder has had to file a Eurocontrol IFR flight plan, and his routing makes use of those routes.
Class E is
uncontrolled airspace for VFR, and this is how a plain PPL can fly VFR in that airspace. UK PPLs call this "flying in French airways" but that is meaningless. It is just a VFR pilot flying in
uncontrolled airspace.
Those suggested routes generally avoid the extensive French military airspace, which makes them extra handy. In fact I have never seen any military activity impinge upon them. The French military have all the rest of France to themselves
As regards EASA officials being dishonest and disingenuous, that is a
fact. Just watch Goudot's "little test" TV performance. Quite what can be done about it is another matter. I think we are stuck with it.
since EIR/IMCr/whatever you call it will/is mostly used by pilots who don't fly that much and use it only as an exit strategy
That is simply not true, but there is a limit on the time one can spend writing here.