The first and most obvious is that (last I checked on Lemmy) per-user instance blocks only block posts, not comments. This means that for truly spammy instances (cough Hexbear cough) it requires an instance-wide block to achieve.

Secondly, I would argue it is the same as any other reason to choose an instance. That being, I have to generally like the vibe and agree with the way it’s run. For example, I have to agree with the instance rules and trust the admins to moderate them. This is an extension of that.

In the case of lemmy.ca specifically, I would say every major defederation I know of has been cast to a community vote and has had solid reasoning behind it. It comes back to trust and matching opinions: I (currently) trust the admin team to have reasonable defederations as they have matched or been similar to my opinions in the past.

I enjoy not having to self-moderate my experience outside of individual users or rare cases. Choosing an instance that generally aligns with your views allows your admin team to do some moderation for you.

Giving away? As in free? Luckyyy

I will never understand how is it that such idiots repeatedly make it to the top.