I'm firmly in the not worth it crowd*... unless you wanted to get an MBA. Even then, if your ambition isn't to climb high on the corporate ladder, then I'd do something else. If your target salary is being achieved by others without master's at your (or other) employers, I wouldn't choose to spend my time that way.
The SAME time spend doing anything that teaches you a trade, hobby, or something else would likely benefit you more. How's your carpentry skills? Can you do more than minor work to your vehicle? For me, these skills have come in 100 times more useful than the masters that my former employer wanted to see me get would have.
If you're an engineer who thinks too much and over complicates stuff, learning the skills above from somebody who isn't an engineer could be doubly helpful. The amount of times I've had my father show me an obvious solution I was missing due to overthinking is staggering. I still don't think like him, but when we work together we're a powerful force. I hope many years from now, when he's not around, I can still hear what he would say to me.
If you already have the ability to do most of these things, or are confident your life path won't require them, do the math on what a flexible hour part time job would do for your life. If you're bored and need to do SOMETHING, then the best value calculation is not Masters or extra sleep, it's 3 years getting a masters vs 3 years of part time job.
As a side note, cultivating a relationship with and marrying my wife was the best happiness and financial decision I could have made because we have similar mindsets about retiring and love each other's company. Granted, our reasons for wanting to retire are different, but our end goal is the same.
*Disclaimer, I didn't like the school part of college, so I got out as fast as I could.