Failure? here you are posting on the Steem blockchain, they haven't failed yet ;)
It also depends on what you are using to measure it, HF20 cut down spam significantly. HF19 did exactly what it was meant to do, then people gamed it with bidbots. They are the only 2 I have been a part of in the 2.5 years on the platform I think.
RE: Beaten HF21 and blue