[toolz]

I doubt any maintainer of a sufficiently popular open source project isn't making a lot of money in tech. Open source can open a lot of doors for employment opportunities and greatly increases your marketability to demand higher wages.

Of course, don't do open source if you don't enjoy it - because I doubt the time spent is optimal for getting the most money, but if you do enjoy it then it can very much help increase your income indirectly.