@Subfader: Out of general curiosity, exactly what is the problem with Comments? As the maintainer and primary developer of it since 2011, I'd be curious to know. :) Its User Interface is pretty stable and definitely not using the latest fancy design things, but it gets the job done. (I'll admit, though, that OOUI did end up lasting for several years longer than it did, but that, too, is being phased out and I'm sure that the successor will also be sunset in favor of a newer, shinier gadget, give it some time. Not using these sort of frameworks comes with the unexpected benefit of your code working regardless, if you can tolerate a somewhat "dated" looking UI.)
For the record: the initial version was written circa 2006 (!) and as it (like other social tools originating from ArmchairGM which enable new content types, like Extension:FanBoxes, Extension:LinkFilter, Extension:Video, ...) predates MediaWiki's ContentHandler system by many years, it does things in a way which isn't ideal, yet it's surprisingly functional and shockingly robust (in my biased opinion), because even major core changes aren't likely to disrupt this little extension which does things in its own way.
Some people argue that "no recent code commits" (or something similar) equals to a dead project. I largely disagree; while it may mean that the end-user should exercise a bit of caution and carefully test things etc., not all MediaWiki developers are huge fans of "move fast and break stuff", which, alas, seems to be all too common these days. Sure, it bumps up a repository's commit count a lot, but what for, and at what cost?
Now, as for Comments' actual architectural shortcomings...while the comments are associated with a(n existing wiki) page, they are indeed in other ways separate, they are not regular wiki page content or anything. So implementing a history interface (phab:T156736) or the ability to undelete previously deleted comments (phab:T127595) is very tricky, to say the least, and I for one would be very surprised (but in a positive way!) to see those implemented before Comments turns 20 years old in 2026.