The current maximum framerate before Unlimited is 255 as standard Minecraft.
I'm suggesting that a new scale is implemented, allowing you to cap your framerate at specific values (or at least add more values), for instance, 1000 or 2000 FPS.
Especially on use cases where you're on power (where you want to conserve battery), and using an external monitor, this feature would be incredibly useful. On my MacBook Pro, on battery, I can easily get over 3000 FPS using Lunar Client and it really doesn't serve any purpose other than taking a hit on my battery use.
Even when using a 240Hz monitor, and using the 255 max framerate, I feel less responsiveness to my game, which isn't an adequate solution to the problem.
Marketing Benefit:
Aside from the power consumption benefits, if you decided to prompt users and suggest they limit their framerate to double their highest monitor hertz count, you could reduce power usage overall.
You can then quantify this and market yourself part of the net zero trend.