As someone who has literally spent dozens of hours researching CPU specs over the last year, let me assure everyone here that Intel is much, much, much better than AMD when it comes to making full stats of their products available.
Sure, you can get basic "speeds and feeds" on most current chips on the AMD site. But anything more than a few years old? Forget it. And the specs they do have are sparse, and often have errors and contradictions.
And the problem isn't even the lack of a proper equivalent of Intel's "ARK". It's the lack of availability of detailed information: datasheets.
Want to know exact details on how memory controllers work, or how PCIe lanes are configured, or pretty much anything else? Intel has datasheets on their site for nearly every chip they've made since the start, detailing every aspect of them in gory detail. AMD? Virtually nothing, and what they do have is hidden in weird places.
People can't even access design datasheets for most of their recent sockets.
My guess is that some executive at AMD decided that this was "proprietary information" and nobody should be able to get it unless under an NDA or something. What is it they are afraid of? I have a hard time understanding how a company in the "challenger" position benefits from specification secrecy when the company they are chasing is so open.