The full story on how Intel managed to fuck up 10nm so badly may not see the light of day for years if ever. But generally, it seems that Intel tried to make too many changes in one generation. They probably wanted their 10nm to be the most advanced process that didn't require EUV lithography. Some features of their 10nm process ended up not working (evidence points to the cobalt interconnects as one of the hang-ups). In the meantime, it looks like EUV is coming along nicely.

They compounded their problems by essentially stopping microarchitecture development on 14nm, which is why eg. their laptop processors still don't support LPDDR4, and they're still shipping basically the same CPU core they released in 2015. Coupling microarchitecture and fabrication development has at times been an advantage for Intel, but for the past few years it's been a huge mistake, and they've promised changes to their design processes so that they don't get stuck like this again in the future if fab advances aren't ready when new microarchitectures are.

TSMC naturally doesn't have this problem, because they're a pure play foundry. Their customers have to each make their own bets on when new fab processes will be truly ready, and how well they will perform in practice.