As you can imagine, instead of intermediaries, AMM, i.e., market maker crypto, is done with the help of automation via smart contracts. There is also an incentive for consumers or traders, in this case, to make sure there is enough liquidity in the market.
Traders can find incentives in the form of age-old arbitrage and slippage opportunities. Further, compared to the fees charged by an intermediary in the Web 2 world, decentralized exchanges or DEXs who use AMM charge very low fees. And note, regardless of whether you are a new DeFi/crypto user or living out of an impoverished nation, you can use DeFi services to earn passive income and make financial transactions for a living.