Out of curiosity, do either of you run uBlock Origin to help block misbehaving background stuff, or any other plugins that might contribute to battery usage?
NoScript really accelerates performance on my FF install. Places like Buzzfeed are unusable on my laptop without it.
Excessive JS usage is probably the culprit behind the move to Chrome. A number of popular sites are so packed with JS that using Chrome is the only way for normal users to achieve reasonable performance.
Nowadays every webpage downloads 2 megabytes of framework JS and css preprocessors and analytics trackers and then pegs the CPU for a few milliseconds to display a paragraph of text.
If the page actually does anything on top of that the problem grows quickly.
Excessive JS usage is probably the culprit behind the move to Chrome. A number of popular sites are so packed with JS that using Chrome is the only way for normal users to achieve reasonable performance.