Years ago I bought a Chevy Van, outfitted as a camping vehicle, and spent a couple of years as an itinerant wanderer. How would I do that using public transportation?

Sometimes, I like to get into my private vehicle and go whenever the wind takes me. I don't think public transportation would provide the same experience.

Mostly, I enjoy traveling in privacy which, by definition, would not be possible using "public" transportation. How does a young couple park in "lover's lane" using public transportation?

Most of us do not experience the kind of discomfort that you are reporting. Public transportation can be a great convenience at times, but for most of us, it will not entirely replace private transportation.