Dark patterns in finding this setting that 99.999% of normies would not even know of, ever. But equally a plausible excuse that "there is a setting to shut it off". Right.
My experience with Arc (which I would assume would be heavier than Chrome) has been that it adds a lot of scary entries in the Resource Monitor App, but doesn't impact my day-to-day use on my 16 Gb M1 MBP.
With Safari, on the other hand, I've experienced audio stutter and delays when using resource intensive wep-apps like YouTube, Figma, Netflix and others.
That would be the case if the Netflix UI was a search box where you type in the name of a movie and then it starts playing.
The actual UI is a lot more complex. On the front page there are dozens of dynamic categories that are filled out with high-res thumbnail images, and the content starts autoplaying within a few seconds when you stop on an item.
Now, I’m not saying that’s necessarily a good interface (personally I hate overactive autoplay). But from an engineering POV, clearly there’s a bunch of prefetching and cache management that needs to happen to make that UI look seamless, without loading pauses or missing content at any step. And media caches do qualify as “resource intensive.”
