Battery disproportionately drains faster when streaming video on normal power mode
I've been testing differences for my M5 Macbook Pro 14" between using normal battery mode and Low Power battery mode. Low Power mode absolutely helps extend the battery life way, way longer, which isn't a surprise. It is expected that in normal power mode, the battery will drain faster. However, though it does drain a bit faster, most of the time it's at a reasonable, expected, consistently predictable pace. I'd say about 10% drain per hour for normal browsing.
This consistency goes completely out the window, though, when you stream a video at full-screen at nearly full volume using the built-in speakers. In Low Power mode for a 25 minute YouTube video, the battery of course drains a little faster than usual, but still not that much - I'd say maybe 5-7% by the end of the video. In normal power mode though, for some bizarre reason, it guzzles so much more of the battery proportionately - more like 10-15% by the end of the video. Practically twice as much as in Low Power mode.
This doesn't make sense to me. The function of the computer on this basic task between both power modes should be the exact same. Even the refresh rate should be the same, since the 120hz wouldn't be kicking in for a normal video at only 30fps. I understand that in normal power mode the computer is doing a lot more background tasks, but it's doing those same background tasks under normal operation too, yet the battery drain doesn't increase as much as it does when streaming video. The speakers perform exactly the same in both power modes too. I don't see how doing this same task in normal power mode should suddenly increase the proportional battery loss versus Low Power mode from normally like 125-150% to 200%.
Any thoughts on how this could be happening?