Revisiting old systems is needed but they obviously don't care about it except for the Graphics Update and sidequest dungeon revamps.

Your idea for fellowships defeats the entire point of them. They help players who "slip through the cracks" and don't have any social circles. They look at them and find communities that way. Their strongest point is being a catalyst for forming a community such as a discord server, an FC, a CWLS, because you can go and invite anyone that joins your fellowship. They reduce the need to advertise things in Party Finder. Multiple of my fellowships reached hundreds of members.