A friendly reminder that isps do NOT care about you or your digital rights. Always best to buy directly from the OEM rather than from the telecommunications (unless you can't afford it). Do proper research before buying a phone!
A lot of carrier phones come with carrier preinstalled apps. And it allows for sim locking, keeping you trapped with them or other carriers on the same network. Or at least that’s how it has been, back in the day, when sim-locking still was legal in the EU. Now, phones are the same, whether they come from your carrier or retail.