ELI5 Recent Crypto Concepts and Arguments: Flashbots, Rollup Wars, etc.

Flashbots is an attempt to make miner extractable value (MEV) have less negative externalities to the Ethereum ecosystem.

MEV is the profit miners can extract from their ability (and responsibility) to order and place transactions in a blockchain. For example, we can imagine a miner and a non-mining user finding a pure profit arbitrage opportunity between two DEXs — e.g. by executing the arbitrage, the trader will turn 1 ETH into 2 ETH. A miner is in a privileged position because if both recognize the trade, the miner can censor the trader and include their version (with minimal gas fees) in their own blocks. Further, since transactions are broadcasted publicly before being included in blocks, miners can observe and copy any such opportunities.