Back in 2018 Marco Arment suggested Low Power Mode on the Mac:
Sometimes, you just need Low Power Mode: the switch added to iOS a few years ago to conserve battery life when you need it, at the expense of full performance and background tasks.
There’s no such feature on Mac laptops, but there should be.
Yes, Yes, Yes!
anecdotally, I’m seeing similar battery gains by disabling Turbo Boost that I’ve seen with previous laptops: significantly longer battery life that I’d estimate to be between 30–50%.
A big +1 from me for a “low power mode” option in MacOS. Add it to MacOS 10.16 and talk about it on stage during the announcement. Brag about how much longer the battery can go in low power mode.
My oldest child has an iPhone 5S and generally leaves it in low power mode all day, as she tends to favor availability over everything else. If there were a similar option in MacOS I suspect many people would do the same thing for their laptops.