The premium from selling options should be proportional to the level of volatility in the underlying. For example you wouldn't expect to take in as much premium on a stock with 45% IV as a stock with only 18 IV. Theres also other factors involved such as the days to expiration, the delta of the strike, and so on.
If the premium earned as % of the underlying purchase price can bring in more than 1% on a 30 day period Im happy because at an annualized rate that is decent compared to the buy and hold returns on the SPY. The return on junk bond fund would be more appropriate to compare than a risk free rate. A 10 year treasury would yield you around 2.3% a year... and its not without duration risk either. At that duration a rise in rates of 1/2% could mean a drop in price of 5%.
But I wouldn't risk capital on any random stock. I study the fundamentals and technical price action first. Then I sell this short put premium on S&P500 stocks I'm willing to go long on at the strike if assigned or willing to hold the stock long when selling the covered call.