The reason the FriendsOfFlarum group came together was to take upon the maintenance of popular abandoned extensions during the Flarum beta cycle and later the 1.0 stable release.
The main goal was not to improve those extensions, but guarantee they continue to work with newer Flarum versions and be secure and performant. Some new features were released, mostly based on very high demand or community sponsors, as developer availability allowed.
Luckily, once Flarum 1.0 was released, the extensions required a lot less maintenance to keep them working. That's why the FoF group has been more dormant recently, the mission does not call for a lot of action.
I am sure that once 2.0 is released, FriendsOfFlarum will rise again to make sure the most loved extensions continue to work with the latest Flarum version. And if it's not FoF itself, other people will pick up those extensions, just like it happened on the 1.0 release. There are a lot more users and developers now than there were back then, so it's bound to happen.
Now for a more personal note, I do have some concerns with some FoF extensions as well. I have seen the amount of bug reports rise, and it can be quite a daunting task to go and investigate each individual report. One problem is that some of these new bugs are a result of the new features that have been contributed, and while I was personally implicated in porting these extensions to beta and stable versions, I never familiarized myself with the new features nor have I the time to study them, so my contribution is limited to asking basic troubleshooting questions and hoping someone else more knowledgeable with the codebase finds some time to look into it. This is why I would overall advocate to keep the FoF extensions as simple as possible. That's easier to maintain, easier to troubleshoot, and mostly maintenance-free in between major Flarum versions.
More complex extensions are probably better left to specific developers or teams of developers, who know their codebase and can provide more efficient help. That's what I do with my premium extensions, they would be way too complex to offer crowd-sourced support.
Another aspect of reading unanswered bug reports can also be that since Flarum has become so much more popular now, there are a lot of users with edge cases. We don't hear from most of the users with regular use cases, but once in a while, someone tries something in a way that was never done before, and this leaves us with questions where we cannot always provide guidance. Sometimes, addressing those edge cases require fundamentally redesigning an existing extension, and this might not be justifiable as an open-source effort.