It's even better in Italy. There's a law called Modem Libero (Free Modem) [1], thanks to that every ISP must give you all the connection parameters (for free) so you can install your own modem.

P.S. thanks, now I know why Iliad (Free in Italy is called Iliad) names their router "Iliadbox" :) that naming is not common in Italy

[1] https://www.dday.it/redazione/51863/modem-libero-e-ftth-tutt...