First, available technical features don't impact community aspects. It's something to be aware of, and influenced my own decision to join toot.cat, though the fact that the admin is someone I've known online for over a decade played a larger role.

Secondly, the issues around moderation also matter, but:

- Blocks are reasonably rare, but generally implemented with good reason. Well-administered instances which play well with others tend very much not to get blocked.

- Increasingly, moderators are sharing blocklists through Fediblock (<https://fediverse.wiki/wiki/Fediblock>) or similar mechanisms. So if a block exists on one well-administered instance, it's likely to exist on numerous others.

- Blocked instances typically have a small number of members, though there are a few exceptions. (Large Japanese instances on which Loli features predominantly is the principle exception of which I'm aware, or alt-right sites such as Gab and Truth Social.)

- Instance moderation is on a continuum. "Limited" simply means there is limited federation, but that content won't appear on the Federated timeline, and that follow requests require an explicit approval. (I see this largely for profiles on infosec.exchange.) That's a relatively low bump.

- Toot.cat does moderate instances extensively, with 476 moderated instances listed at <https://toot.cat/about>. 138 of those are "Limited" (see above), 338 are suspended, meaning no federation occurs. The top 20 moderation rationales are:

50 Reason not available
18 Freeze peach instance
17 Transphobic admin
11 Admin using a wide variety of slurs
10 Admin using racist slurs
10 Covid denialism
8 Edgelord admin
8 Racist admin
6 Lamp instance(s)
5 Admin shitposting to #fediblock
5 Anti-moderation admin
5 Cryptocurrency-oriented instance
5 Harassment, slurs, fascism, etc.
5 Transphobic harassment from admin
4 Adming spamming #fediblock
4 Anti-LGBTQ+ admin
4 Conspiracy theory
4 Covid denialism and other disinfo
3 Admin using ableist slurs
3 Anti-moderation instance

"Freeze peach" is often code for limited or no moderation, and is associated with pronounced and unaddressed abuse. "Lamp" is a specific abusive user, see: <https://mew.toot.cat/mw/Usr/lamp>.

I haven't (yet) checked to see how many profiles exist or are active (w/in the past month) on the blocked instances, but I strongly suspect that most are quite small, or no longer active. Just for grins, I'm looking at a random selection of 10 instances blocked by toot.cat ('sort -R | head -10' off the list of blocked instances):

neckbbeard.xyz: Server not found
hermitmountain.top: Timeout on Web access
dobbs.town: Timeout on Web access
ortodogs.info: Unable to connect
touha.me: Single-user
nnia.space: 282 active users (blocked as pedophile instance)
gamers.exposed: Appears inactive? Video site?
neenster.org: Unknown (users not reported). Principally Nina Paly's personal instance as I understand.
cybercriminal.eu: Timeout on Web access
mastinator.com: Read-only implementation, presumably no users.

So that's 2 actives out of ten listings, with the largest having 282 members (small by Fediverse standards).

Keep in mind that blocks are appealable, both by the remote instance and local users. And the threat of blocks is a strong incentive for both admins and users to execute and expect effective and socially-conscious moderation. Edgelords can play, but they'll play in a vastly reduced space.