According to the source, MEV allows block producers to reorder or insert transactions, enabling sandwich attacks and arbitrage that worsen user pricing and operate like a hidden tax on Ethereum swaps. Source: Ethereum.org MEV overview; Daian et al., Flash Boys 2.0. For traders, this increases effective slippage, raises the risk of failed transactions during volatility, and materially widens execution costs on AMM venues such as Uniswap. Source: Ethereum.org MEV overview; Qin et al., 2021 research on sandwich attacks in decentralized exchanges. Mitigation options include routing via private orderflow and MEV-aware intents systems, such as Flashbots Protect and UniswapX, which are designed to reduce or rebate MEV to order originators. Source: Flashbots Protect documentation; Uniswap Labs UniswapX announcement.