the stat passives are not cosmetic. they are serve as pathing.
Mind over matter is 7 passive points from witch start, via stat nodes.
or, is it 10 passive points, with cast speed, damage, and arcanists dominion? that pathing also moves you closer to practial application, and heart and soul.
or 7 to mom, +1 to arcanists dominion, and
MoM is 11 passive points from Scion.
Mom is 16 passive points from Duelist.
theres three key factors in there. 1. every passive is potential an option to every class. 2. the passive cost to each class varies based on starting location. 3. Pathing to one key node, reduces the passive cost of other nearby passive keystones.
the visible tree system is the best way to do this.
you COULD just have the passives open, and add variable costs based on class. like say, melee passives cost 5,10,15 points for a melee class, but cost 7,13,19 for hybrids, and 9,15,21 for casters. and then you COULD add synergies. where taking some caster passive, reduces other similar passives. but this system would be hidden and arbitrary. The Pathing tree adds very simple to understand visuals, and adds a whole minigame essentially in finding the most efficient path.