Street Photography, the reason why I find it so insanely fascinating is because of the fact that it requires insane amounts of courage. I truly believe that street photography is 99.99% courage.
Also, with street photography, it is like an adventure. To travel to foreign places is an adventure. Also, to put yourself in situations which require courage is also an adventure.
There is no end limit to photography and street photography, given that you will continue to travel intermittently for the rest of your life.