Taking care of bonsai is a lot of work. It often involves slowly cultivating and manipulating the plant to grow in a certain way. At a botanical garden in the US, they had a small bonsai that traveled from Japan that was over 1000 years old. Knowing that many people took good care of the plant all those years through many generations of history is an art of itself.
Like art, it's not for everyone, but some people enjoy the process of caring for a bonsai. This is what some people did during their past-time before technology existed to entertain us now. It's subjective.