Here comes the ceiling. Those who reached heaven through ritual enjoy its vastness — but only as long as their merit lasts. The moment the punya runs out, they return to the mortal world. 'Gatagatam' — this coming and going never stops.
It is like a prepaid card. You load it with punya through yajna. You spend it in heaven. When the balance hits zero, you are back where you started. The pleasures were real, but they were rented, not owned.
Krishna does not say this path is wrong. He says it has a limit. For those driven by kama — the desire for enjoyment — the cycle of rise and fall continues. Moksha requires stepping beyond desire altogether.