What are some ethical ways of making money in this system?

Whenever I think of doing something to generate extra income, it feels exploitative or taking advantage of others. I think about those people and wonder how they sleep at night knowing they took advantage of others. You could get a job and get exploited which is better than being on the other end.

The problem is that I'm already doing a full-time job and my income is nearly not enough, barely making ends meet and in my developing country, you can't get much more than that without engaging in some sort of business aka exploitation. I wonder how other left leaning people survive financially under these conditions.