You could be right. I just started with 500px. We’ll see how it goes.
The main appeal for me of Flickr is that I can dump large quantities of photos on it and leave judging and using them up to others. Maybe I can do the same with 500px, but it seems to me there is more of a pure quality orientation there, so photos can be sold. Maybe, if Flickr lives, I can vet thousands of photos there while offering dozens for sale with 500px.