What’s a for-profit attack?

I’ve heard this happens a lot with some mining pools since they’re centralized and can pick which transactions go into blocks, along with pulling off other tricks. But I’m a bit lost on the specifics of how this attack really works, either supporting or challenging the consensus rules. How do they exploit these rules, and just how easy is it to target the consensus with such an attack? Is there any strategy or approach the Bitcoin community uses to counteract this, and can they also pull off double spending? I’m new to this term, so any insights would be appreciated. Thanks!

Yeah, I've read through this, but didn't know how to share a clickable link that'll lead to the exact place where I saw the term, however, regarding the double spending, a mining pool (not saying their operators are into such practice) control about 28-31% of the total mining hashrate according to mempool stats, and I just figured that it doesn't really have to be 51% of the hashrate to perform a double spend, that 30% can also execute such an attack. Hence, if that's possible I think I'm clear about the double spending capability of for-profit attack. As you can see the term wasn't explained in details, that's why I asked here to know more about it, the techniques and what can be done about it. Your answer is good, moving people away from a suspected mining pool controlled by tricky operators can help reduce such threat by diminishing the hashrate of the pool, yet it's written that if it's been done carefully they'll go unnoticed. So, I'm wondering if no method exist that can bench or stop for-profit attackers even though a mining pool does that secretly. Or its centralized nature keeps the for-profit attack operators immune from sanction or restriction?

The pool can add any transaction to the block, but I don't understand how the mining pool can include double-spend transactions if it's not a 51% attack. There were commercial attacks in Ethereum, because the order of transactions was important there and Maximal extractable value (MEV) appeared.

The 'double spend' comment is wrong. The consensus rules disallow it. If a pool or miner starts double spending, they will be off on their own fork and not mining Bitcoin any more. The only option with 'double spending' is to effectively roll back the block chain and cancel the spend with a new spend to a different address. However, this would also be blatantly obvious that the pool did it, so they would be crucifying themselves.

I explained a method of for profit attack which a large pool that keeps fees can do it is in a sticky thread. https://bitcointalk.org/index.php?topic=2634505.0 The only way to prevent this attack is for miners to not use pools that keep fees.