I set a rule for myself: when I see on-chain what looks like a "seemingly free" arbitrage opportunity, I first assume it's not a chance but an entry point where others are waiting to collect my fees.

The sandwich thing, to put it simply, is that the moment you press confirm, others have already laid out the tablecloth before and after you, and you only see the meat in the middle.
Recently, with staking, shared security, and yield stacking causing quite a buzz, the more "layered" it gets, the more it seems like risk stacking and then selling you a story.
Anyway, I’d rather earn a little less, take it slow, and not treat drawdowns as tuition paid to robots.