You can collude to attack, but that would be visible.
Nope.
Please re-read my prior post.
Attacker only needs 51% of hashrate to censor transactions perpetually (and less % to delay transactions).
To censor, he has to orphan other miners' blocks that do include the transactions. That is visible. Delaying is possible without creating forks. Censorship is not.
I had to teach monsterer that your assumption is incorrect. Why don't you ask him about our prior discussion in the Decentralization thread on this topic:
Also I already explained upthread that an emphemeral fork (which orphans another chain) can't be blamed for a double-spend or censored transaction, because there is no provable correlation. Seems you've forgotten where I had to teach you in my Decentralized thread why it is
impossible for a minority chain to prove anything (because the state of the chain is never absolute w.r.t. to any external chain/clock and is always moving forward). Which is the same analogous
mistake enet made upthread.