There are limitations, but not as bad as you might think.
https://www.cnet.com/news/sprints-free-year-of-unlimited-data-whats-the-catch/
https://www.sprint.com/en/shop/offers/free-unlimited.html?ECID=vanity:1yearfree
https://www.cnet.com/news/sprints-free-year-of-unlimited-data-whats-the-catch/
https://www.sprint.com/en/shop/offers/free-unlimited.html?ECID=vanity:1yearfree