weird build contradiction... (power charge on critical + controlled destruction)

I'm following this elementalist Arc build, and now that i am at a halfway respectable level with a few options i am wondering why the build is telling me to link my ark skill this way

Arc - power charge on crit - spell echo - added lightning dmg - lightning pen - controlled destruction

i am loving the build so far and I have no complaints, but the power charge on crit and controlled destruction seem like a major contradiction.

i am pretty much a know-nothing who needs to rely on other ppls expertise. Maybe yal can explain it to me?

The controlled destruction does not remove all of your crit. It just lowers it. IF you have not used PoB(Path of Building) I highly suggest it, it will allow you to see how the gems affect each other easier.

why are u even respond without explaining how controlled D actually works?
Controlled D works like that:

Your spell (in this case Arc) has 5% basecrit value.
So Controlled D takes that value and reduces that by 100% so if u have like 50% crit it will reduce it by 5% so u end up with 45% crit

hope it helps :)