It's not income. It's positive cash flow with an offsetting negative obligation. It's not risk free. It's taking a risk to (hopefully) earn a profit. If I short a stock this collecting positive cash flow, it's literally the exact same trade. So why are we calling covered options "income," and can we please stop already?
Edit for clarification: are you withdrawing that premium when you close those contracts? If not, it's account growth via risk aka cap gains like any other investment or trade, not income. If I short stock, is it income? No, and no one refers to it as income. Because it's nothing until it's closed, and then it's a gain/win or a loss. A dividend is income. It goes to my bank/cash account with no obligation to take additional risk. A sold option that is closed for profit or expires and stays in your account is a cap gain. Income implies you get to go spend it. And of course you could. But I could do the same with a gain from a stock trade. And we're not walking around calling that "income," now are we?