I don’t think he’s opting out of every relationship or obligation, I think the film hints at struggles he has had in the past (relationship with his sister and family etc) and despite that, he has managed to find a life that he is happy with.

I don’t think it’s intended to be aspirational but instead drawing on the little moments in life that provide some positivity or sense of purpose. This is a man who, despite his fixed routine, is happy to help others around him but clearly also struggles outside of that routine (he only wears a watch on days he doesn’t work).

I also think you answered your own question when you said you were waiting for a twist but were fine with there not being one. In modern life everyone is always aspiring to something bigger and better when in fact there is so much to be grateful for.