An instance being blocked by all other instances?

No, defederating is just a single instance blocking another instance, not the entire fediverse doing so.

I’ve read that too, but I still have the ability to add a custom list. It says initially, so I assumed they got around that issue by now, considering it isn’t the case for me.

I technically use Edge which afaik still allows MV2, so in case the extension somehow implements both and defaults to mv2 if available, I’ve decided to install Chrome and get ABP there to test. Even in Chrome, the ability to add a custom list is still there. As are all the other features, like manual updating. With custom list I mean both the ability to add a list per URL, and the ability to add custom arbitrary rules directly.

I don’t really see why element blocking wouldn’t be possible or allowed under Manifest v3. Like, it’s entirely client-side. Manifest never comes into play there.

What I can imagine is that custom lists might work that same way too, removing the ads from the page after they’ve already loaded rather than blocking the web request directly which is afaik how adblocking works in mv2. I can’t tell you if that’s the case or not.

Probably because of the Adblock Plus mention. It’s mired in controversy because of its acceptable ads toggle and requiring ad giants to pay for it. So I can imagine people downvoting comments that put it in a positive light compared to other adblockers.

I’m a bit confused as an Adblock Plus user, why did the ublock dev drop those features? ABP uses manifest v3 too and it still has all of those. So it’s clearly not about them being impossible.