It’s not the browser but the websites.
Two way video streaming will be always resource intensive.
But for the other websites the choise is yours, you don’t have to use amazon or goog, there are alternatives.
Also if you doesn’t have enough ram close the tabs. My 10 years old low end laptop with 8GB ram, I know I can’t have more than 6-8 tabs open at the same time.
I guess you write about the base64 images.
I tried some of them none of them work, they are truncated to 255 characters. I checked the history of some and all of them was added in iD, JOSM gives you a warning if you want to upload a value longer than 255.
Maybe they should be removed?