France prices are only due to Free mobile. Before they came up with their 20€ a month plan with unlimited everything, the other operators mobile plans had prices similar to the US, 60 to 80 € a month for unlimited everything.
There was rumors of free mobile acquiring T-Mobile sometime last year, that would have been awesome for US consumers...
That same 20€/mo plan gives 25GB of data to use abroad, which makes project fi a less interesting option in France.
While you’re right that Free Mobile indeed had a big impact on prices in France, I’m pretty sure prices before Free were closer to 30-50 € euro a month and not 60-80.
With that said, data usage habits also did change between 2012 and now. I was happy with 500 Mo/month back in 2011. I would have trouble living with that now.
I mean, I think you could say the same about practically anywhere in Europe. Irish mobile prices were horrendous until Three showed up in the early noughties, say. But that's the past.