On-chain this kind of "queue jumping," to put it simply, means someone can see what you're about to do first and then decide whether to let you go ahead. You think you're just doing a swap/liquidation, but you're actually providing others with a free roadmap. The biggest impact isn't just "retail investors getting liquidated"; market makers, liquidators, and even the protocols themselves are forced to add protections—without them, they'd be drained; ultimately, the costs are passed on to slippage, fees, and user experience.

Recently, with extreme funding rates, the community is again arguing whether to reverse or continue squeezing the bubble. I’m more focused on on-chain congestion and how many "clamps" there are: the more volatile the sentiment, the more valuable this small privilege of order sequencing becomes... You ask, "What should I do?" I’d suggest fewer chase trades, avoid overly aggressive market orders, and use aggregation when possible. The rest... forget it. As for you saying "MEV actually improves efficiency"... well, efficiency has increased, but whose efficiency is hard to say.