The world of imbalanced markets
For a market to work you need to trust it. More specifically, you need to trust the outcome of an interaction with the market. When there are just a few people in a market and you know and trust all of them; you can trust the entire market. As a market grows -and users become anonymous – then you need a trusted party/operator to have a trustworthy market.
When operating a market, rules are needed to define which objectives the market will prioritize because you simply can’t make everyone happy (see the century or so old discussion about the objectives of the money market: should it prioritize the value of financial assets with stable money/deflation or growth with inflation and devaluating financial assets?).