Before the Universe Magic Pool shattered, regardless of how powerful the gods were, they couldn't directly send an avatar to Feinan.
It was also because of this that they couldn't show their "miracles" anywhere other than the secondary planes and had to develop their believers there.
That, along with the firm Wizard Rule, led to the current situation in Feinan. Few people had faith in gods.
Of course, there were still some believers in some areas.
For example, the Silver God and the Craftsman God were different because they didn't need to display miracles, as they would gain faith anyways.
But most gods weren't known, or more precisely, the masses didn't know clearly about their existences.
This was the reason they wanted to attack the Universe Magic Pool.
The New Gods from the 3rd Era that originally came from Feinan but couldn't even send an avatar there were understandably very annoyed.