[newishuser]

To me, the main effect here is that you have an excuse to stop thinking about the other options. There has been a ceremonial decision making process, and because of it your mind can rest. It's the same as writing your choices down on strips of paper and pulling one out of a hat. That process, that ceremony, gives you piece of mind, not "what you actually want to do".

This is more an exploitation of the human brain's tendency to romanticize chance than an actual method of decision making. If your decision is so arbitrary that the outcome of a coin toss will mentally satisfy you then you've already made your decision; it's both, just pick one. Theres no magical insight into your soul going on here just whatever you thought of while the coin was in the air. If you had tossed the coin at a different time in the day, or perhaps right after seeing an ad for KFC maybe your 1 second decision would have been different.