You would be surprised at what breaks. It also prevents local storage (not just cookies) from working at all when inside an iframe. That took me a long time at work to debug.
More importantly, instead of silently failing like localStorage should, the attribute on the window object is missing, causing page scripts that don't catch the exception (ie all of them) to crash and usually break the page.
I'm pretty sure Google is making disabling cookies as painful and breakage-inducing as possible to make sure
people don't flip the switch.
I'm pretty sure Google is making disabling cookies as painful and breakage-inducing as possible to make sure people don't flip the switch.