Like which ones? Not being sarcastic, I just can't think of any off the top of my head.
(on Facebook core product)
I am leaving out their never really widely launched crypto hype disaster of a product on purpose.
These are pretty major, successful features that drive a lot of use.
I don't disagree with your main point, though: Facebook certainly developed lots of new features, whereas Twitter pretty much stood still.
I don't have any insight into groups, but I do into Marketplace where yes it absolutely did.
I'd be astonished if Pages didn't have a measurable effect too since they are one of the main ways brands (which is a major source of FB revenue) interfaces with FB.
* Facebook Apps (not really a thing anymore. Maybe it still exists)
* Facebook Games (remember Zynga?)
* Facebook Deals (they were taking on GroupOn)
* Messenger (as a separate product. One of the most heavily used products in the world)
* Events (which for many people is the only reason they have an account)
* Facebook Groups (still heavily used)
* Facebook Pages (still heavily used)
* Facebook Video (still heavily used)
* Facebook Marketplace (extremely heavily used in many markets)
* Stories (still heavily used)
* Reels (sort of merged into Videos)
* Facebook Places (big plans, but died)
* Facebook Graph Search (nothing like originally released: https://en.wikipedia.org/wiki/Facebook_Graph_Search)
* Their add platform is truly terrible. Ask anyone who deals in that area to compare it with Meta or Google's and they will laugh.
* They can't ship new products. Since 2008 they have increased the size of tweets from 140 characters to 280 characters, and that is the biggest change. Look how many things Facebook has tried in the same time. Some failed, but lots succeeded.
Also in the history of bad decisions, surely the decision to kill Vine is right up there? Occasionally people still find an old Vine video and share it. What could have been...