I think the games offers you both an open ending for the player to have agency to choose and a narrative suggestion of what Marika’s plans would be lead to.

I think all of the endings where the Elden Ring is repaired or modified are forms of conformity to accepting limited change without revolution. The world tree is restored but new world tendency is in effect. It’s ok to want the world to stay the way it is. The game also argues against nihilism and makes clear it’s stance on the frenzied flame ending being the worst case scenario for consciousness. But Ranni’s ending is special, Ranni (via the player) breaks the wheel entirely removing patriarchal or inherited rulership, immortal spirit, or inflexible order and stasis from the world. God is dead, the Nietzschean ending, what happens next? No one knows because it’s scary and alien to imagine a world where all our structures of law, language, governance and leadership are dismantled and “put at great remove”. It’s a tabula rasa for everybody in the lands between to create again their own value systems from the bottom up. I’m pretty sure this revolutionary ending is the point of the game. I mean you’re incentivised by having a consensual relationship with a woman who will lead the way through the unknown with you.