Earlier quoted context omitted.
To be honest, all browsers currently on market are energy hogs and use massive amount of memory. God I miss the old Opera....
I do wonder how much of that is the browser's fault, and how much is because of website developers not understanding that we have a website obesity problem[0], nor the concept of "optimizing for fan noise"[1]. I'm fairly conscientious about this myself since I'm working on plotting data, and the dumb client-side number crunching involved is actually pretty good at eating CPU cycles. Most plotting libraries want to sh…
I think some of it is also that the web has numerous things about it that are fundamentally expensive operations, going back to things like "the default table sizing algorithm reacts to the flow of the content within it, which also depends on how the table decides to format it". It's not hard to create a pure HTML page that has no interesting images or scripts or anything, but still is fundamentally slow to render. (You probably wouldn't want to write it by hand, but I've accidentally written programs that output such pages over the years.)