This was the compulsory requirement of a Tier 6 world!
In other words, in a perfect Tier 6 world, unless there was a vacancy, or even if he had the foundation and qualifications,
They would not be able to break through either!
To put it bluntly, it was.
So what if you have the qualifications and conditions?
He was still unable to break through!
Unless there was a vacancy.
Only then could they break through!
It was the same for the Ancestral Realm of Apocalypse.
As for why there were such rules.
This was because Tier 6 worlds had Great Dao structures.
The structure of the Great Dao meant that this Tier 6 world had already been recognized by the Great Dao!
This was equivalent to having an identity card in the Great Dao.
One carrot, one pit. There were no exceptions if the accumulated foundation was reached.
He could go to the other Tier 6 worlds and try his luck to obtain a spot!