It's late in that nvidia had this performance level a whole year ago. The PC world moves fast. Coming out a year after your competitor with a product that only matches their performance (and it is highly unlikely that AMD will be able to match perf/watt or OC capability) for the same price is a great way to make yourself irrelevant.
AMD either needed a bigger polaris to fight the 1070 or needed to release vega. They did neither, and now face a market that already has the performance AMD is offering.
The failure that was bulldozer/piledriver/steamroller/excavator was a monumental failure, but as much as people want to blame intel/nvidia, AMD did this to themselves.
The core 2 came out in 2006. It took AMD two whole years to strap some L3 cache onto their core design, and they failed at doing even that.
AMD mismanaged the entire ATI aquisition, and payed far too much inthe process. They also failed to properly merge these two separate workforces for almost a decade. They also took nearly as long to finally get ATI's drivers close to nvidia's quality wise, and even then it took nvidia having an attrocious year of releases for it to happen. Even THEN, there are still some long running bugs that have not been fixed.
AMD spent 9 months rebranding their 200 series under the guise of preparing new GPUs to fight nividia, even though they had a newer arch (GCN1.2/tonga) to work with, and plenty of time to implement it. 1.2 was already taped out, they just needed to make more GPUs based on said design. the 300 series proceeded to bomb, resulting in AMD's lowest marketshare in their history of GPUs.
AMD launched a GPU line that was only competitive with 2 year old maxwell chips, and left the mid range, high end, and halo markets completely untouched, allowing nvidia to rake in cash. Even though there were plenty who would buy AMD in sheer spite of nvidia's dodgy business practices, AMD just sat on the tech and did nothing with it. This also cost them most of the dGPU laptop market, another major money maker for nvidia.
AMD sabatoged their entire CPU/APU lineup. After seeing that the construction core was an abysmal failure, they continued to push it, moving their APU line to bulldozer (and wiping out the good momentum Llano made, as bulldozer did terribly in low wattage situations) and allowed OEMS to make abysmally low quality laptops with their chips for years. Then AMD proceeded to claim they just were not going to compete with intel, shaking whatever trust they had left.
Everything up there? all AMD's doing. Not intels, not nvidias, not the illuminatis or gods, AMD's. Intel dug a small hole, AMD made it into a grave and willingly buried itself in it. So yes, I am critical of AMD, because this is a company that has had many great technologies and proceeded to obliterate their own company instead of capitalizing on that tech many times over the last decade. Somehow, I have doubt that a company like this, that has botched launch after launch, can pull off making a VEGA chip that is competitive, especially given their lackluster budget and the splitting of resources between vega and polaris. 3DFX couldnt do it at the height of their power, somehow I feel that a bruised and broken AMD cant do it properly either.