Rowan's bloodlines fed on his Origin Land, destroying it and consuming countless tonnes of earth, enough to build a hundred universes every year, and this was just the beginning.
Even though his dimensional flesh could withstand this amount of deterioration, that was only for the short term; not even a Primordial Domain could endure this sort of consumption for long.
As the strength and appetites of his bloodlines increased, his dimensional flesh and Origin Land would be destroyed; it was inevitable.
This would take a long time; perhaps multiple Major Eras might pass, but his Origin Land would inevitably be consumed to nothingness. But that would only happen if Rowan had the trait of destruction.
If Rowan controlled only Destruction, he could still cultivate despite the consumption of his bloodlines on his Origin Land, and he would reach the level of a Primordial.