They are a tool to be used where suitable and not the answer to everything. They are significantly better for detection and classification than what came before

They are a tool to be used where suitable and not the answer to everything. They are significantly better for detection and classification than what came before but improvement has plateaued. When they fail, how and why is not characterizable. They're good for some things but you have to be careful about how you build the whole system and not just throw a CNN at it unless you really don't mind undefined behavior.