Other Battery - Why does video playback last longer than web browsing ?

[fourchannel]

Iphone 12 estimates 17 hours of Video browsing and yet if I get 6 to 8 hours of OST for web browsing, that is considered acceptable.
How does video streaming eat up less battery than just web browsing ?

I noticed the M1 Macbooks are the same with 20 hour video playback vs 17 hour standard use.

 

[Girder_Shade]

Video playback is predictable and steady. Processor only has to worry about processing video data and displaying where web browsing is unpredictable and erratic. You are constantly clicking on links, displaying pictures and gifs and videos. The processor is working hard to push through everything you are trying to access randomly.

 

[JPack]

The Wi-Fi and cellular radios use a lot of power when in operation. Streaming allows the radio to download large blocks of data and quickly power down.