The problem with that is balance and design. FFX is a single-player game and PoE is also mostly played solo or in very small groups, and is a classless system to boot (mostly). There are no DPS meters to show you what setup is the absolute best, no difficult team fights where one person underperforming player can mean the raid doesn't progress, no Warcraftlogs-level spirit of competition within the same group, no tight balance required between classes, no PvP to balance either which is a whole other can of worms.
Thus having this massive tree where most options would inevitably be deemed suboptimal (as is the case with PoE in the end, let's not kid ourselves) wouldn't change much to the problem we sometimes have now where 1, maybe 2 talents in a row are worth it. And creating your build only works if you're mostly playing your way, by yourself. Once you enter difficult and competitive content in any game, cookie cutter rears its ugly head if it is the only way, or only perceived way, to advance.