Intel's deathgrip rests on four factors: - Intel's "deal sweeteners" (preferential pricing et al), which they can't afford to do forever. - Intel's ability to provide the whole stack (chipsets->boards). - Corporate IT's sclerotic processes (not always a bad thing BTW though personally I find it stifiling). - Server chip architecture.
It will all come down to money. If AMD parts have good performance/cost/power consumption points, you'll get AMD laptops (is thunderbolt 3 silicon available for AMD? I don't know).
If they beat Intel on server performance why wouldn't everybody switch? AMD doesn't appear to have the full AVX instruction set but I'm not sure how many people really use that.
Corporate IT's process is mostly about money, holistically (does it give us volume pricing? Does it reduce support cost?) as corporate IT is always a cost center. So they'll switch if it's worth it.
So you're right that Intel will continue to be dominant for a (relatively) long time, but for the reasons above that's more about market hysteresis than fundamental superiority, which Intel still has in certain places but which has eroded mostly across the board for a long time. And the kicker of hysteretic phenomena is when you reach the critical point you can't really get back.