I do live near Bergerac airport, in fact using it in a few weeks time to fly to Stansted. as it suits my travel plans - most times it doesn't.
But for the last 3 to 4 years I have gone to Bordeaux simply because the flights with EasyJet are so much cheaper than Flybe.
Save once, when there was a RTA, my journey time to Bordeaux has been consistent at approx. 75 minutes. OK, I am a hyper "get there in plenty of time" nerd, drives my wife wild, but that has nothing to do with the actual travel times.
And since Merignac is whole much nicer experience than Bergerac, I can deal with my choice of extended waiting time.
But I agree with the general comment that these regional airports cannot be economic without subsidies. I seem to recall that there was an extensive campaign by Brussels, Paris and Air France to stop these.