Collectively, the core species were pretty one-dimensional, and there were almost no variables you could play with.
What if Earth Ponies lose their connection to the land?
What if pegasi lose the ability to fly and control the weather?
What if unicorns lose their ability to do magic?
What if alicorns lose the ability to move the Sun and Moon?
End of Equestria as we know it. There’s no in-between.
So exploring the long-term consequences of that is kinda the only place for the show’s universe to go while keeping it about the ponies. If G5 is a setting where the Earth Ponies are rediscovering their connection to the land, Pegasi are re-learning flight, Unicorns are re-learning magic, the three tribes are figuring out how to get along, and maybe the other species are poking their heads in, then the setting actually has somewhere to go, even if it’s just back to where G4 was.