edocali
Someone I worked with thought he didn't need insurance for a weekend skiing in the Alps as he already had comprehensive international private health cover & the flights were just cheapo easyJet ones.
When he ended up in hospital he was fine all the costs were covered but once discharged it cost him just over £45k for a private flight home as none of the airlines would take him. It was an insignificant sum to him but would have been a problem to most.
Yours is Not the scenario initially discussed, that is, only cross a country (France) where travel insurance won’t pay, to get to another country (Switzerland) where all is good.
For this scenario (which matches mine) I don’t care if travel insurance is not valid in France.
Spending your holiday in a country where you have no cover is a different risk, imho.