I'm not sure that we are browsing the same internet, but many sites made with React and similar do utilize an entire core, so you do need a powerful processor.

I'm not sure that we are browsing the same internet, but many sites made with React and similar do utilize an entire core, so you do need a powerful processor. It's one of the problems people are trying to solve with server-side rendering and resumability, to only execute the JavaScript on the client needed for interactivity, when it's needed. Obviously the machine is a tool, to be used for what you need it for. Just because you have a genitalia capable of making a thousand children it doesn't mean that you need a thousand children. Besides children are expensive to have, and so is electricity. Batteries don't grow on trees either.