Commuter diaries - The 1 perfect bike?

Is there such a thing, a one bike does everything perfect machine. I'm someone who has 1 of everything: a tourer, MTB (HT and Suspension), road bike, folder, but do I need them all. By having many bikes do I not spend enough time on any given one? Dilemma, which is my favourite (I know, it's a nice dilemma to have) and I guess I am spoilt by the nature of my work; but you know, sometimes I would just like, the 1 do everything bike that I will ride every day for the rest of my life, but maybe this doesn't exist? I have horses for courses, each bike is great for different reasons and they all have uniquely different ride characteristics. Thankfully I have space and an understanding family, can I slim the stable down, so to speak and spend more time on each bike?

That's the Winter challenge, "less is more" - John Ruskin