Think about things from the point of view of someone who has never used Reddit or the fediverse, but you've heard about them both from recent news articles and want to see what they are about.
Reddit:- You Google Reddit and your first result is Reddit.com. You click the link and are presented with the front page. You from scroll from a few hours and end up signing up and staying.
Lemmy:- You Google Lemmy and your first result is a wiki article for Lemmy Kilmister... Your second result might be join-lemmy.org, which you're smart enough to realise it's probably more likely what the news is about.
You click join-lemmy.org and are presented with a page of information about the fediverse, links to set up a server and pictures of code...
There is very little chance you're going to investigate further.
If we want the fediverse to replace Reddit then either
A) Lemmy needs to improve its initial impression and Search engine optimization
B) We should be promoting a different platform with a better initial first impression.
I'd recommend kbin personally as it gives the same sort of experience as Reddit from the initial interaction.
If kbin/lemmy/the fediverse are to be something the average reddit user wants to migrate to, then a lot of ground has to be covered still. There is no "reddit migration" possible or remotely likely without significant change, as much as I want the fediverse to succeed and as cool as I find it
"If" is doing a lot of heavy lifting there, to be honest.
The average internet user has been ok with everything collapsing into a monolithic search engine and 4 giant social websites owned by 3 guys.
Maybe we accept complexity and expect a little more out of the people who end up here. People whole like what things have become can stay where they are.
The average user doesn't want to migrate here, though. The average user is either content to keep their Reddit account or thinking on migrating to another big centralised platform.
Open-source decentralised platforms like the fediverse and its projects aren't remotedly interesting for the average user.