I rebind mine to control.
> whats the benefit?
Control is an actually useful key, in Emacs specifically but also in OSX in general as all OSX controls have emacs-ish chords support (e.g. C-a C-e for start and end of line). Having Control on a large well-placed key is more convenient than have it on a small key in the corner, and I've literally no use for capslock.
> how do you turn on caps?
I don't think I've ever wanted that in the last 20 years or so, every single toggling of capslock has been by mistake. In fact one of my issues with windows is there still isn't a way to easily remap capslock, it takes 3 clicks in OSX (or ChromeOS), it takes installing third-party software or hand-rolling custom keyboard layouts on windows.