Fifa license is worthless without Fifpro
Historically a lot of shitty games had great sales because they had a popular IP from movies, comics, etc in the cover. Independently of the game quality or the developer.
FIFA is now one of the best selling series in gaming history, each year they sell like 20 million copies. FIFA is now a top brand for the casual gamers. Whoever puts FIFA on their game cover will sell a ton of copies.
FIFPro deals aren't exclusive, so if 2K, Konami, Sony, Sega or any other company have enough money and want to spend it as EA does, they can also license all these players, competitions, stadiums and so on. The more money they put, the more and better teams and so on can license.