It may be that some products conflict with internal business requirements. Google Reader was brilliant because it brought the internet to you but it also meant pages werent being clicked on and ads weren't being viewed; I would posit RSS loses websites money so they hide it away.

One thing I would question: do users and companies ever drop apps because they are just physically uncomfrtable to use? https://carlst-james.medium.com/ergonomorphism-next-big-thing-in-ux-f895495051ed