Probably a very polarizing question.
On the one hand, having most of the users and communities on LW causes technical issues (see this post), and also gives the LW staff too much power over Lemmy as a whole.
On the other hand, with 18k MAU on LW out of 47k (https://fedidb.org/software/lemmy/), every community listed there has a much higher chance of visibility compared to an alternative hosted on another instance
History of LW controversial decisions
- when they promoted Discord as an official communication channel (https://lemmy.world/post/3478399 - since then they created a Matrix chat)
- when they blocked the piracy communities (https://lemmy.world/post/13320356 )
- when they announced they might move from Lemmy to Sublinks (some comments from LW admins were quite controversial: https://lemmy.world/post/13899357 )
- when they forced the media bias fact checker bot and discarded user feedback (https://lemmy.world/post/18775630 - to be fair, they since then removed it from !news@lemmy.world , it’s still in !politics@lemmy.world )
- when they realized centralization of communities on LW was impacting the ability of other instances to stay up to date (https://lemmy.world/post/13967373 )
- when they updated their rules following a power trip overtake of a community (https://feddit.org/post/2308651 )
Or there aren’t enough specific ones. If you go to Join Lemmy and you are presented with a number of general purpose instances, you are likely to pick the largest and only later realise the problems that entails and switch to another instance.
If you are a Trekkie or read books or game or program then it is easy to pick one. Ditto if there is an instance specific to your country (I should know).
If you look at Mastodon (which is more developed and has a wider and deeper selection of instances) you can see that these niches instances do well and I think we need to encourage more here.
Can confirm that when choosing a Mastodon account, .social wasn’t taking new users at the time. So I looked at the list and chose vmst.io because “Oh, I’m a nerd too.”
I’ll say that while the number of connections is far lower, so far I haven’t noticed that as a problem in the limited capacity that I use Mastodon.