Tell me, do you pay the same to phone someone in the UK from Norwich as you do from Normandy using a BT or SFR landline? Do you pay the same to send a letter or parcel within the UK or France as you do to send a letter or parcel between the 2 countries?
In my experience the UK is MUCH cheaper for postage both inland and from the UK to France, postage in France is not a cheap option and there seem to be a lot of petty restrictions about how to package items for postage which are unheard of in the UK....... they seem to require an awful lot of things to be packaged in a cardboard box bought from.......
You guessed it, "La Poste" this they justify by saying that they do not have doorstep deliveries, but everything is delivered into the required Post Office box with the approved key so that the Postperson (in our case a sweet lady) can open the box and put parcels straight inside - that makes deliveries much easier, and presumably quicker than ringing a bell and waiting fora non-answer. But the cost is high......
As regards phone calls, our landline package (UK Telecom) gives us free calls to UK landlines and to French landlines AT A PRICE. Calls to mobiles either in France or the UK are expensive and calls to 0345 or 0800 UK numbers are NOT foc. That is just the package that we have (although we are looking at changing it but sadly we cannot get broadband via ADSL or anything other than satellite, so we tend to try to use What'sApp and Skype when we can...... But communications (like most things in France) are more expensive than in the UK as the idea of "competition" does not exist - monopolies rule the market and customer service is non-existent.
Since you are so knowledgeable about what IS going to happen please explain why, as part of the Brexit negotiations, is it so impossible for the UK to remain in the 'no roaming costs' area, after all many EU citizens travel to the UK with their mobile phones too. And if we do not remain in that deal, then I am sure the vast majority IN the UK won't see it as the end of the world.
I totally agree that the cost of reintroduced roaming charges is not even a minor point - it wil be less significant than that for the vast majority of the UK population who rarely venture into Eurpe other than perhaps a week or two for a holiday sitting on a sandy beach, drinking English beers and consuming English food in English pubs and restaurants. In other words it's like Exmouth but with more sun and warmer water to play around in - not really the same as going to see "Europe".
Reintroduction may well affect people who use their phones/tablets/laptops etc for business use and I am sure many will look for alternative ways round the cost by e.g. buying local sim cards (if that is possible), perhaps through new businesses set up simply to allow people to do that with the minimum of hassle.
I don't think that I have ever said differently, roaming charges are very minor c/w general living expenses and many people are unlikely to even notice it (unless they leave data roaming switched on by accident and suddenly find their iPad has been charging them a fortune to update all of it's bits and pieces several times a day......).