There's a 3rd party website to make your builds with better features but it's still a mess, the concept is convoluted as fuck in general. As daunting as the skill tree in PoE is, it's fairly simple, you get one point, you put a point in something next to something else you took before. There's various paths and optimization but if you're a Witch and want Mind over Matter, it's very clear how to get it.
The devotion shit has the added layer of need the required amount of colored points to put points into the next constellation and every constellation gives different amounts and different colors and then there's a lot of optimization by taking like some constellation to afford another then unspecing out of the first because the 2nd gives you enough points to activate itself.
And then it's really hard to tell what is even good. PoE keystones are simple enough at a look, Cannot be Stunned but Cannot Crit or Reduces your life to 1 max but Chaos Immunity and Chaos doesn't pierce ES anymore. While a lot of the big constellation stuff is like some proc that does 5things but you can't really tell what it's good for because you don't know if it's a pbaoe, a projectile, what size it has and then you can only see the lvl 1 of it so you don't know how well it scales or not plus you have to think about how many of these procs you get because you have to associate them to an active skill so you have to plan for that.
It's kinda varied and adds some nice things to an otherwise bland skill system but it's really super complex for a new player other than putting points in random shit or following a guide.