Firefox works fine and I like the privacy focus and general features. However, it still randomly causes the CPU usage to spike and makes the fans run full tilt

Firefox works fine and I like the privacy focus and general features. However, it still randomly causes the CPU usage to spike and makes the fans run full tilt (top shows 90-100% usage for god knows what), even when the same tabs are open doing the same things. I don't see this (atleast not as often) in Chrome, which I don't want to use, but end up using it until Google does one more privacy destroying thing, in a long line of such things, which makes me angry enough to go back to FF until the cycle repeats. I guess I have resigned being like a ping-pong ball bouncing between these two browsers.