You shouldn't be comparing salaries like that. You might be right to count your salary and find it to be higher than your friends salary. But the thing is, you are NOT paid by hour. Say you wanted to earn an equal salary as your friend. You can choose to work OT for as many hours as you like but you will not have a rise in your pay.

Based on the pay/hour you are definitely better off but when it comes to how much compensation you can get with your current position, you will never be on par unless of course you get a promotion or pay rise, but thats out of context.

You talk about monetizing your free time to "Earn more". Sure you could do that. But would you actually do it? Would you enjoy doing it? (since you said its about being happy) If you enjoy working an extra job that pays more (by hour) than your current job, you might as well quit your current job and work full time on that. If the extra job pays less, you wouldn't want to do it because you would think that for working more, you should be at least getting the same pay as what you would get in your current job.