Yes...you are actually right (finally). Yoga and other practices are designed to induce such a sense of fulfillment.
Almost certainly they are designed to induce an increase in anandamide serum levels which cross the blood/brain barrier to induce the effects you describe. We know this now, but of course when people were developing yoga and similar practices they didn't now this albeit they felt the effects induced to be important/significant etc etc, but the reality is that the effects are physiological, and pretty well understood physiology now.
But the problem is...that is not enough. We need to explain Life, Mind, Consciousness, Death, purpose and so on. That is where a broader philosophical framework becomes necessary.
These are entirely different questions - we can ruminate all we like on life, death, purpose etc etc, but the effects you've described are almost certainly a simple chemical process in the brain.
Chance, random variations, NS and emergence ...are just not good enough.
Why aren't they enough - if they are able to adequately explain (based on evidence) why you feel as you do when you think god is around, or when I sing in my choir, or when VG goes skydiving, or when someone practices yoga, why do you need to ascribe some greater purpose. Realistically the only 'greater purpose' you need to include is evolutionary benefits as it is pretty easy to see why the release of anandamide, triggered by certain experiences may be beneficial.