These days, I've been staring at the mempool until my eyes hurt.

You could say the sandwich thing is an opportunity, but more often it feels like I'm just helping others pay transaction fees...
Once I saw a large swap and thought I could take advantage of the price difference, but I impulsively clicked it, and the next second I was caught in the middle, with slippage fully eaten, like the bus just arrived and I was pushed off—such an awkward moment.

Now new L1/L2s are starting to offer incentives to attract TVL, and old users complain about "mining, selling," which I can really empathize with:
On-chain, it looks lively, but many transactions are just to move subsidies away, while using you and me as liquidity.
Honestly, sometimes the difference between arbitrage and a sandwich is just a thin layer: you see an opportunity, but others see your next fee.
Forget it, I better hold onto that "ticket" tightly so I don't get on the wrong bus again.