While I agree that (in theory) more choice for the user is better, I'm not sure that this is necessarily the best in practice.

Already, two main roadblocks to fediverse growth are "it is confusing" and "there is insufficient activity in any given community". Presenting new users with too many options exacerbates both of these issues.

I don't disagree in general, but from practical standpoint it's a technical barrier that is already being partially addressed with mobile clients and is actively supported on platform level Support for grouping communities / multi-communities.

And confusion around Fediverse doesn't get solved by this. It doesn't help them understand how instances work or why there are different domains for various communities. And those users that migrate would still be confused when they navigate to All feed.

To attract Reddit users, the bar is higher than one might think. I'd say at least 10% of the activity of the corresponding subreddit at the bare minimum, preferably closer to 30%.

I fundamentally disagree. You won't move over established posters. It's partially due to the sunk cost fallacy, but primarily they just don't want to move. They like where they are. People should have learned that lesson after the failed blackout. What the goal should be is to convert lurkers into posters.

Would you be able to provide some examples? I've heard this before, but no examples come to mind. If anything, I've found the reverse to be much more common: A bunch of communities on the same topic splintered across different instances, none of which have enough activity on their own to maintain an active community.

Both are true to some extent.

Take Tesla communities, as an example.

There is !tesla@lemmy.world and !realtesla@lemmy.world one is focused on strictly Tesla, another allows general political posts that involve Tesla CEO in non company capacity. There is also a divide between the type of user that interacts in each of them based on what gets actively downvoted.

Then there is also federation aspect. Some instances have aggressive defederation policies that cut off large chucks on the users. Are those users not entitled to have a community where they can interact just because their instance have an issue with someone? And yes, they can move or create 20 different accounts across the Fediverse, but that would go against your point of usability and accessibility.

Or various World News communities (some allow US posts, while others categorically don't). Some only allow posts from certain sites, while others are more open. Some enforce specific post formats, while others don't.

But the rule that has the biggest number of disagreements seems to be social media posts. Some communities gets flooded with screenshots or links to social media, and then an alternative community pops up that doesn't allow that.

There are also many cases where bad moderation decision lead to alternative communities being created. Star Trek (moderators of popular community had strong opinions about a particular season and starting removing user that disagreed), Science Fiction (main moderator was removed for disagreeing with instance admins for comments unrelated to the community), there is also a strong sentiment that lemmy.ml communities removes differing point of view which leads to alternative communities, and many more cases.