So Life Siphon effectively converts their slaves into spiritual batteries and tonics for them. They can use their slaves to replenish their spiritual energy or to heal themselves when they are injured.
Or for fun, pleasure, and punishment, they can just straight up kill their slaves through the mark of bondage. Either way, they think that the Life Siphon divine ability is worth the lack of an increase to their perception and spiritual energy capacity.
On the matter of the pathway of the telepath, instead of getting a quantitative boost in their power, they got a qualitative boost. When they were at rank 1, they could only estimate emotions, but now they can read minds.
No matter how much spiritual power, perception, and spiritual energy they have, it will never be able to match the ability to read minds. So they think it is also worth it to forgo a boost to their spiritual energy and perception this rank.
