So replace religion with unscientifically naive optimism? That too is a delusional narrative. "Donating your atoms back to the universe" as if a personified "universe" cares about you on its way to heat death, someone get me my spirit crystals.

You might say you're off the religious dance-floor, but you're still doing the moves. In fact it's almost more rational to get back into one of the holy books, at least there you can connect the dots on attaching meaning to the present.