It is tragic: Failbetter years ago offered a game engine called Storynexus (site is preserved, but new worlds cannot be created) which was an author-friendly version of the Fallen London engine to build similar worlds that included monetization. Unfortunately it was not financially viable and they shut it down.
Another similar engine was Varytale which was more story-focused. If you’ve played Emily Short’s BEE that was the one game that people knew about. Varytale shut down, and BEE was recreated using a built system called Dendry which I as I understand isn’t web/user friendly as the original Varytale, but can be used to create this type of story.
One other suggestion before building your own entire system: There is an extension called Hybrid Choices for Inform 7. This allows the author to switch from the parser world model of Inform into CYOA mode which displays “pages” and numbered choices which can affect and be affected by rules and the existing world model which many people are familiar with using. Theoretically a game could just use the choice mode and Inform rules. I was able to use it to change choice text with Inform text variation (which can include percentage chance of success or give an explanation what the choice does), and remove or enable choices based on world state, including any stats you create for the player.
Examples of Hybrid Choices in use: I used it for conversations and complex interactions in Fair and Steph Cherrywell uses it for dialogue in games such as Zozzled and Brain Guzzlers from Beyond.