The problem with street photography, so to say, is that you need time. A lot of time.
Effectively, if you spend a whole week in Tokyo, London or NYC, every day wake up early and spend the day and the evening in interesting areas which are well frequented, armed with a few batteries, a M mono and a 24mm lens … well you would be surprised how many keepers you will have at the end of the week.
I bet 10 good pics per week are possible.
Remember, what we see on the Flickr stream is just a very very small fraction of what was shot.
Over time you also get better, shooting from the hip, zone focusing, etc.
Add to that post production and chances are you too or everyone for that matter can crank out some great shots.
But to find the time … an M11M with a Summilux 24 (out of production) will give you already perfect quality to work with and print large