Of course, there was a huge difference between Vaan's Heaven's Swallowing Space and a Divine Cultivator's Divine World.
The Divine World was like a planet governed by the five elemental laws. On the other hand, the Heaven-Swallowing Space was like an empty universe, governed by pure spatial law.
One could support life but not accommodate many things; the other could accommodate all things but not support life.
That said, Vaan didn't feel like it was an impossible task to create habitable worlds within his Heaven-Swallowing Space. He already had some comprehension of space, time, fire, earth, water, wind, life, and death.
He believed that once he raised all these laws to a certain standard, he would be able to create a more complete life-accommodating world than the Divine World. Moreover, it wouldn't be limited to one world but many worlds, mirroring a miniature universe.
