It really isn’t easy to make any fair claims about memory usage unless you’re being extremely careful. The browsers and apps do all kinds of crazy caching with freely available memory, for performance reasons, and they can get by with a lot less than what you’re quoting. Try seeing how memory scales if you open 10 or 100 tabs. It might seem super bloated until you’re about to run out of memory, and then somehow seemingly magically be able to still open two or three times as many tabs.