Other games only need talent trees because you're locked into a single class on a character so you can't really have a varied experience in gameplay. They're not needed here because we can be all classes on a single character. They tried to something with cross-classing in the past, but it just became cookie-cutter where everyone was expected to level the same classes and have the same cross-class abilities. They just got rid of cross-class and made some of those role abilities.