Instance blocking in Connect for Lemmy also hides all comments from all people in the blocked instance. It doesn’t make them disappear like blocking a user does, but the comment appears with the body text replaced by a button that allows you to optionally unhide the message (like how Discord used to hide messages from blocked users).

I never used that app but I can tell that it absolutely is not how blocking in the Lemmy back-end works, I’m not even sure if it adds insance blocks to the user’s account when using the feature or if it just keeps them client-side, since that feature existed long before Lemmy itself had the option. Regardless many people don’t use connect, especially desktop users (connect is a mobile app) so for them it won’t work the same way.

Defederation should literally be a last resort option IMO. Otherwise you end up like Beehaw: isolated on an island away from like 90% of the Fediverse. Great for moderation but terrible for discoverability and growth.

I would agree but it’s important to realize where that line is, and to make sure it’s reasonable. Defederating Lemmy.world because of their bad users isn’t reasonable (just ban those specific people) defederating hexbear is, because their instance is entirely dedicated to spam and trolling, it’s a matter of community health, it’s not just because they’re annoying or we don’t wike them.

As an example, I like anime. Let’s say hypothetically that you don’t like anime and that I have an account on your instance. And let’s say you hate anime, actually. You want your instance to defederate from ani.social (and any other instance that hosts anime content) because you hate anime, but I don’t because I like the memes and discussions from there. How do you resolve this? Now think about what happens with an instance that hosts content that is of a different political ideology than you. Its really the same problem.

I don’t think this is really a good comparison, you’re framing it like every call for defederation was founded on personal opinion as opposed to said instance’s impact on community health i.e. Hexbear’s tendency to spam and harass people, or ExplodingHeads and their tendency to attack users of minorities (particularly gender diverse folks). Lots of people will feel these bans infringe on their freedom, yet these are for the good of the community. It’s important to remember that most lemmy instances (the ones still in the main network) are not and have not been free speech havens. When these types of guidelines aren’t enforced you get communties very similar to 4chan and gab, where the loudest ones rule and push out everyone else, it’s the Nazi bar problem. This isn’t really comparable to admins blocking instances out of personal preference, which is in a sense a form of malpractice, this is a form of moderation meant to keep spaces sane and normal, otherwise people won’t want to be their and it’ll become a Nazi bar (or Tankie bar in the case of Hexbear).

Lemmy does best when it gives as many options to its users as possible, including preferring local user instance blocking as compared to defederating.

I think you’re thinking of Nostr, Lemmy is very much a power to the site/administration type platform. They’re the ones that have the final say, they can literally ban your account from the entire network and prevent you from even logging in (on your Homeserver). The big difference between Lemmy and mainstream centralized sites is that there’s more than one of them, so if you do get nuked on one you can go elsewhere, or even start your own. Same thing when it comes to instance defederation. The user options are the servers they can choose to home themselves on, not being exempt from moderation requirements or overriding admin’s decisions. If a person doesn’t like that aspect of mainstream media, they’re going to hate Lemmy just as much. Lemmy isn’t a free speech user choice haven, it is social media free from central corporate influence (for the most part, corpos can start their own, whether instances follow them or block them is a different story).