In my never-ending quest to minimize distractions and maximize efficiency in my work — a quest that's especially challenging this time of year! — one thing I've discovered is that notifications tend to be detrimental to productivity.
Think about it: By their very nature, notifications are distractions. They flash and ding and steal your focus away from whatever Very Important Task you happen to be doing at any given moment (even if said task is simply staring blankly whilst thinking of cake — hey, we've all been there). And more often than not, your allegedly smart phone's notifications don't involve anything that actually demands your immediate attention. Pardon my gibberish, but that's pretty flarking stupid.