It is slightly more complicated. Yes there are laws against it.
For example, in a majority of states in US, including Ohio, if an amateur takes 3rd party money, they are no longer an amateur.
The situation with Zion Williamson and Duke is a great case study in this. Zion says his initial contract with first agent is null and void because they discarded NC law that would’ve made him ineligible. However, the agency is saying you were never technically able to play at Duke because you weren’t an amateur.....you were taking money from Nike. You weren’t a college amateur.
Bottom line, states need to adapt amateurism laws to protect college athletes getting paid $$$$. Florida has cleared it........I just hope we don’t miss a recruiting cycle because the state has missed the boat on college athletes being able to do car commercials.