I'm trying to keep the "basics" part of the site simple, while those who want more in-depth details about specific Fedi server types can look at the "beyond mastodon" section lower down the page.
Roughly speaking, the lower down the contents page you go the more complex the information.
I would definitely call these choices rather than deficiencies. The more features you add to software, the more resources it takes to maintain and design. Also, some developers might want to keep their software as focused as possible. I don't think PeerTube was ever meant to be for microblogging, for example.