Lemmy (or at least lemmy.world) was bonkers levels of buggy last summer during the reddit blackout. Like, literally unusable levels of buggy. Getting the word out that it's (mostly) bug-free now would probably be good, because I'm sure there were many redditors who tried it and quickly swore it off as a pile of shit.
Otherwise I'm in agreement that the instance-selection part of sign-up is a huge barrier, because what instance you choose is actually really important but it's overwhelming when you're just getting started. Plus not being able to migrate your account/communities/posts to another instance if yours goes to shit/shuts down/turns out to not fit your needs makes the fediverse feel really unstable.
The difference is if the primary (sometimes only) admin of your instance loses interest, goes to jail, or gets hit by a truck, your entire instance could be dead in the water, whereas there are way more safeguards to "established" social media like Reddit and Twitter. Plus the issue of "well shit my instance got defederated from most of the fediverse because it turns out the admin is an asshat" is completely nonsensical on platforms without instances. Example: before I knew that Lemmy had a tankie problem, I almost signed up on lemmygrad because I thought it was just a witty pun...
Plus when you say "point them to lem.ee" what scenario are you imagining? Because "you should join reddit" or "our business is on Facebook" or "Twitter is a great resource for artists" are all straightforward and easy pieces of information to convey and pick up. "Join Lemmy, a subset of the fediverse, I signed up via lemmy.world although I hear lem.ee is also good, but don't let that stop you from picking another instance" is like... Dude, people just want to go to [site].com, click on "sign up", enter a username and password (and maybe email) and that's it. Just having to explain to people that "lemmy.com" isn't a thing is already too complicated for most folks.