Overclocking (for me) is not meant to be run 24/7. Of course its anyone's prerogative, but personally I prefer to have the option to overclock and use that option in games when my target framerate is not met. Or in the benchmarks I do from time to time for my Youtube channel.
Let's say I play witcher 3 and for the settings I am using, I am around 50ish most of the time. If I don't feel like fiddling around with the settings, I can try to get +20% performance through overclocking. Now if for the length of 2-3-5 games, I need to overclock to get the performance I want and doing so I lose the power efficiency, so be it.
If I need to overclock all the time for the performance I want, then I have gotten the wrong card, but usually I don't.