What is Notebook.ai?
Notebook is a set of tools for writers, game designers, and roleplayers to create magnificent universes — and everything within them.
Comments and Reviews
Said about Notebook.ai as an alternative
Similiar, but not as good. Far less questions, but you can add your own custom questions.
Notebook.ai has a way cleaner interface and seems a lot easier to use. You have to pay to get private pages on World Anvil, but that's a free feature on Notebook.ai and it seems to have a lot more features geared towards writing and worldbuilding instead of just playing RPG games.