This is an interesting spin on trying to optimize power efficiency. It's similar to TLP, but instead of trying to optimize everything, it simply targets the CPU.

On a laptop running on battery, cpufreq can go into a low-power energy saving mode, but still boost the CPU for demanding tasks without the need to manually set the CPU to performance mode. This makes it a more 'set it and forget it' app.

This should also work on desktops, and could save you a few watts if you mostly use it to idle around in a browser all day, and only occasionally stress the CPU with a game or other task.

If you don't care about automatically switching to a higher performance mode and instead want to prioritize power savings, such as on a laptop, TLP is still possibly better in that regard (and if you do go that route, be sure to use the TLP GUI