There are shades of gray between the people who understand the technical definition of federation, and people who, as you put it "browse the web by accident". The people who are looking for an alternative right now understand e-mail well enough (from an end-user perspective) to make the comparison.
If we ever get to the point where enough people use mastodon that the latter category would also be interested in participating in it, it would be so ubiquitous that they would ask someone with a minimum of understanding to et it up for them. Just the way it works now with other things.
Every point of friction you add for a user of a new thing is a reason for them to abandon it. Even if Mastodon isn't trying to necessarily replace Twitter, catering only to the most dedicated users is not a way to grow a healthy community.
Here's a story about an engineering professor lamenting that their first-year students do not understand folder structures, because they have been using Google Docs for a decade, and don't use use anything besides the search bar.
https://www.theverge.com/22684730/students-file-folder-direc...
That's not to say they're obsolete but it's not necessary for whole classes of users to use and understand them.
I would posit that it's easier to understand things like objects, arrays and API endpoints if you have that basic familiarity with folders.
In many cases hierarchies are just ceremony or boilerplate that slow down a user. Say a note taking application. It can store the actual notes in a database that can sync between machines and the web. Using search to find notes, especially if it supports some sort of inline tagging like hashtags, is faster for the user than trying to come up with some folder hierarchy. Hierarchies also are inconvenient when documents straddle multiple categories. Grouping by tags let a note/document exist in multiple categories without reorganizing everything.
Thirty years ago the only "view" into storage was directories and files. File systems were relatively sparse in terms of metadata support. Directory hierarchies were the only tool for organization. Information Retrieval systems were all about adding an over the top database and document indexing system on shitty sparse file systems.
Today a lot of those Information Retrieval concepts are rolled into online storage systems (Google Docs etc). So hierarchies aren't the primary organization unit since they're not the only mechanism the backing store has for organization.
Non-technical users have never understood these things. They browse the web by accident and sending e-mail is incomprehensible magic. Most people don't care at all how such things work, they only care when they don't work.