Many DAOs have massive (>$1B) treasuries that are used to fund development and marketing. Developers propose OSS projects and these orgs give out grants based on community votes. See https://gitcoin.co or the Uniswap Grants program for examples.

You create a decentralised service that crypto companies need, and then add a native token for governance. Governance token ends up having value (more than it should in a lot of cases) and the developers profit.

For example, people initially just had crypto tokens. Then came uniswap liquidity pools for exchanges. People could suddenly earn interest on their crypto. Uniswap creators profit.

Crypto organizations hire, give grants & ofc anyone can buy a token [if there's one present] & start writing code / content etc. to make that token more valuable.

For many, their wealth is derived more from crypto / token capital gain than traditional income. Its increased risk no doubt. More upside & downside.