You're ignoring the fact that many users have applications other than a browser open, and that those applications also consume memory. Start hitting the swapfile and any performance advantage disappears. It is in the best interest of everyone to make applications use less memory, since all the applications (and the OS) have to share what the system has.
> It is in the best interest of everyone to make applications use less memory, since all the applications (and the OS) have to share what the system has.
There is always a trade-off between speed and memory usage. For my use cases, I prefer this particular trade-off for a browser. I realize you might not have the same preference.
