They stumbled on 10nm is what happened. They expected their manufacturing prowess to continue to let them build massive dies. So now they're stuck with CPU arc

They stumbled on 10nm is what happened. They expected their manufacturing prowess to continue to let them build massive dies. So now they're stuck with CPU architecture designs that mandate huge dies to scale up the core counts, which they can't manufacture with anything close to reasonable yields on 14nm. Rock meet hard place. AMD by contrast designed with the expectation that they couldn't make big chips, so went with a "glue a bunch of small ones together" design. Which seems to have played out stunningly well for them. Now they can bin the golden cores, slap them together, and ramp the clocks.