If you own stocks, and the stocks produce a dividend, which is a share of the profit from the company, then the stocks are producing income passively for you.
Stocks are my favorite asset right now. I invest simply into index funds that track the total stock market.
As we get closer and closer to our retirement ages, people want to make sure their assets can cover them as they age.
Owning assets makes this machine roll. The more you own the less you have to work at your job. That is the name of the game. Work less and get paid more.