@sarmale exactly. I saw on r/RedditAlternatives that someone created a Lemmy instance that was defederated from everyone - so it is possible to turn your Lemmy server into a walled garden. Maybe an allowlist would make for a better middle ground.
We simply need a lot more moderation tools than the current set of lemmy devs are willing to create, and many of them see some of the requests as frivolous or not in line with their personal beliefs on how the website mechanics should work. There's also a metric ton of bugs, potential legal issues with how the platform deals with federation and malicious and abhorrent material, and the issue of the code of choice this website runs on not being a particularly popular or easy to pick up coding language meaning less access to talent to fix or work on new things. We've been talking about potentially moving platforms for some time now and with time there are just more discoveries of new issues.
I will be honest with you, I do not think that it would be a good use of your time. This has been unfolding for a long time and its clear that there are both coding and ideological issues with lemmy as a platform (there's plenty of discussions of this which have unfolded in the chat and beehaw support communities which I would suggest reading up on). However, if you are committed to making lemmy as a whole a better place, here's a truncated list of some of the still existing issues:
There are not enough federation options to deal effectively with current problems, at minimum:
One-way federation to protect our site culture
Exemption from all feed & media reject to handle pornography
Purging posts and comments does not purge associated images
Reports are not sent to the right places (example: we don't get reports about our users' off-instance activity and reports are not sent to moderators which are off-instance)
The modlog does not work in a chronological fashion and does not allow to filter actions by instance or per community
Moderators are exposed to graphic images because a banned user's description is still visible
If you are a mod of a community, and you get banned from that community you mod, you can still take mod actions
If you get site-banned from an instance and you are from another instance, you can still post on the community and people from your instance can see and interact with your posts