So apparently Earth's tectonic plates are moving more quickly than they used to because the earth's core is cooler.
Could that be true for street art? Is it evolving more rapidly because it is cooler?
That would possibly be true if you agreed with the assumption that mainstream popularity equates to cool. I happen to think that the opposite is true.
Probably the saving grace is that alongside the socially popular work continues the stuff they don't like. So it is that boundaries continue to be pushed.
And it seems this art is moved by the hotness, not the cool.