Here is proof:
The only websites I have open are this page and a YouTube video playing at 1080P (highest resolution):
This page is taking up 2 GIGABYTES of RAM while the YouTube video only 358MB. I've seen BF take 3GB of ram, but I didn't screenshot it.
Ask your devs why it takes 6x as much memory to render this text and image website than it takes to run 1080P videos
