Its an optical illusion that the cost of that Power Charge is less efficient than any other on the tree.
I know this will be downvoted but mathematically that three points is identical to the 3 points a Templar would have to spend on a PC, and the 3 points a Maruader would have to spend on a Endo charge etc. The optical illusion of "wasteful pathing" is purely selection bias. You're counting the extra line subconsciously as waste. The extra connection gives the appearance of inefficiency even if none exists.
I too will sit there and look at triangular connections and try to figure out how to eliminate them even when they are identically efficient with any other pathing.
For some proof lets look at the identical situation in Templar and then at the end we'll talk about Nullification comparing it to the similar Templar notable "Elementalist" to illustrate. So lets say we take both the PC and the Jewel. To make it easy to illustrate we path from the closest main starting notable (Trickery for shadow for example) through the INT shortest path to the charge in both cases (makes it an apples to apples comparison because templar doesn't have a crit wheel) then on to get the jewel:
- Templar from Retribution notable to PC and then Jewel socket: 10 passives
- Shadow from Trickery to PC and then Jewel Socket 9 Passives
Now if we take Nullification and Elementalist, the Shadow spends 2 points for a total of 11 and the templar spends 1 point for the same total. Nullification is also a significantly more powerful node than Elementalist and the single travel node is an eHp node not a stat further increasing the value of pathing to it.
This comparison goes even more heavilly in Shadows favor if we use the southern routing and go for the Frenzy charge, jewel and Nullification where the total cost in passives is 10 points.
I realize crit builds will want to path through the crit making it no longer apples to apples but in terms of straight Tree design, that Triangle is not inefficient in fact it appears to be returning better passive value at the same or lower cost.