Recently, I saw retail investors complaining again: validators are earning income while also having to manage "fair ordering." Frankly, what everyone is criticizing isn't the technology itself, but the feeling of being cut in line. Actually, you can simplify a bunch of terms (data availability / ordering / finality) into one line: what you send out, can others see it (availability); after seeing it, in what order do they include it in blocks (ordering); finally, can this process be reversed (finality). If any link loosens, MEV has a gap, and the opportunists love to exploit it.

Forget it, speaking plainly: don't just focus on "Did I buy at a high price," first ask "Was I cut in line, can it be revoked?"
What I care more about now is: what guarantees do the chain/rollup provide on these three matters? If there's no guarantee, just assume it will eventually cause trouble. Take a sip of tea first.