I think most of the functions could be covered by other extensions at some point in the future. And speaking as someone who has no experience at extension development (😂) I personally I feel that's the best way forward, by breaking it up into multiple extensions.
For example, extensions we have today that could play a role.
- Likes
- Reactions
- Ranks
- Badges
- AutoModerator*
AutoModerator can be extended by other extensions to provide actions, metrics and requirements. This allows you to setup automation to (as an example) grant or remove ranks/badges to users based on any available metric such as likes, reactions, or any other extension (current/future) that wishes to provide a metric. That provides similar functionality to one part of Gamification (ranks based on points), though of course this way you could select your own way to calculate the points by including whichever metrics you want into the criteria for that badge/rank.
So what's missing? Well there's no rankings page. But one could create a Rankings dashboard extension that could then perhaps can integrate with AutoModerator to leverage the metrics other extensions make available to it. Maybe that makes that ranking dashboard extension more dynamic, so you could even create multiple ranking page instances that are based on the different metrics available (top poster of the month/all time, most helpful user of the month/all time, most karma this month/all time).
Some of this is already possible (Granting Badges based on likes, best answers), some would require existing extensions to add the integration with AutoModerator and some parts could be available through future development. Is it a pipe dream? Tbh I don't think it is, especially with the extension development we've seen for Flarum over the past year.
Just my thoughts 😃