That is done, but you need a lot of capital due to bitcoin's slow block times. You'll need to have capital on both places to take advantage of the price differe

That is done, but you need a lot of capital due to bitcoin's slow block times. You'll need to have capital on both places to take advantage of the price differential since the price will shift to much by the time you migrate funds from one CEX to another. But this post isn't about bitcoin, it's about Ethereum. Ethereum is where all the innovation and most of the financial activity occurs. Arbitrage MEV comes from different onchain decentralized exchanges, slippage, defi liquidations, etc.