Something that rarely gets addressed in these discussions is why Ethereum even has fee market to begin with instead of a cheap FIFO model which ideally would be

Something that rarely gets addressed in these discussions is why Ethereum even has fee market to begin with instead of a cheap FIFO model which ideally would be more fair. To answer that I would invite anyone to try using a blockchain under heavy load without any way for users to prioritize transactions. What you will find is the network becomes vulnerable to transaction spamming; possibly to point of breaking consensus making it so nobody can transact at all. MEV is a consequence of a design decision to address this. And that's not to say Ethereum has everything figured out and a better FIFO model can't solve this, but afaik this is the current state of things.