The EU has ended the days of mobile roaming rip-offs
In the days when there were hundreds of mobile companies around the world, one could understand that each company paid the other for any calls and data use on the host’s network used by visiting customers and that this might lead to higher call charges.
But today many of Europe’s mobile operators are owned by one of a small number of groups. Locally they may act as separate companies but at the very top they’re part of a single pan-Europe group.