Why is the processor so loaded when playing video in the browser?

Question

Browsers

Sub toaster. Tell me how to fix this misunderstanding that the browser eats up from 30 to 80% of the processor at the time of video playback. Why is this happening ?
Browser as seen on picrelated
firefox. It's not about a bad flash player because the screen was made when playing in an html5 player , it's also not about addons because the screen was made with completely disabled add-ons in the browser .
This situation is observed in all browsers. The only difference is the number of processes. So in Chrome 30-50 processes can be created with 2 open tabs, in firefox by process per tab and some additional ones. processes that I discovered for example - "windows audio device graph isolation".
This question is very important for me because I constantly use the browser, well, as well as everything else.
Info:
OS: Windows 10
Browser: firefox 44.0.2
Processor: AMD A6-4400M APU with Radeon HD Graphics 2.70GHz
RAM: 6Gb
Campluchter: Notebook HP Pavilion g6

Answer 1

https://www.cpubenchmark.net/cpu.php?cpu=AMD+A6-44...
everything is ok, this one should load 70%

Answer 2

Most likely your vidyashka is too old, and it does not have hardware support for video decoding, so the percent is loaded.