There seems to be consensus about their 10nm failures: they were trying every trick in the book except switching to EUV lithography, betting that they could get

There seems to be consensus about their 10nm failures: they were trying every trick in the book except switching to EUV lithography, betting that they could get ahead and stay ahead while EUV power levels creeped upward toward what's needed for volume manufacturing. But Intel bit off more than they could chew and ended up with a process that simply didn't work (cf. the disabled iGPU on Cannonlake). So Intel scaled back their ambitions and spent more time working out the kinks, and they're apparently still a year away from having a 10nm desktop CPU. I'm not sure if we have any good clues as to what's going wrong with Intel's 7nm efforts, but it seems reasonable to guess that they weren't putting as much effort as their competitors into getting ready for EUV. And given how long Intel's had these issues at this point, it seems pretty clear that they have some broader management issues.