It’s all just a vestige of FF11 and 1.0 roots..and to a lesser extent, Dungeons and Dragons.

Such a system requires extensive balancing and robustness to be useful, otherwise people just meta it to choose limited “best” options (see Guildwars 2), which makes it simply illusion of choice.

At the end of the day, simple but elegant is best when development time is limited. No need to make more work for yourself for little profit, right?