AMD has been doing custom x86 SoCs for a long time, mostly for game consoles. It hasn't had any real impact on the laptop/desktop/server market so far.

That was to be expected, PCs as phenomen only happened due to IBMs mistake of keeping them vertically integrated as all the remaining 16 bit platforms.

Modern laptops and mobile devices reflect a return to the vertical integratio of those computing devices (Atari, Amiga, Macintosh), with PC towers becoming a niche market and businesses coming back to timesharing.

So yeah, it will happen.

yes. Apple making their own processor. Google making their own processor, and so on. the generic x86 as we know, might be dead soon.