So, e.g. Telia doesn't have to pay any roaming charge to WIND Hellas if a Telia customer from Sweden goes to Greece and connects that network?
Previously I heard a cap of 7 € per gigabyte for data fees was regulated.
If I divide my monthly internet bill with the amount of data I transfer during it, then price of GB of data transfer is indeed close to nothing.
But even the most price-gouging "captive audience" transit providers (e.g. in data centres without multiple choices of carriers) rarely charge more than ~$10/Mbps (depending on utilisation down to ~$40 per TB transferred or about 0.04 cents per GB...)
The EU parliament wanted to go much further, starting at 4 and gradually reducing to 1. They'll get pushed further down eventually, but at the same time nobody wants to overdo this and cause problems for these providers by going too fast.
Now those operators that have been competitive will suffer. Those that have been extractive towards their own customers and their competitors will benefit.