Why blow it? Because they both live on borrowed time. Whatever they do ARM is going to storm the x86 castle sooner or later, and there will be no survivors.

The logic is simple. Neither Intel nor AMD has anything unique that the ARM side cannot replicate in one way or the other. ARM is currently edging out x86 in the supercomputing space (Fugaku), in the server rooms (AWS Graviton2 and Amphere Altra) and in laptops (M1). The only patch of land that x86 still holds onto is powerful workstations and gaming rigs. But there is only a question of time before there will be a better ARM alternative. Nvidea is buys making ARM solution. Not sure when but pretty sure Nvidea will be capable of creating a more powerful gaming rig than x86 can compete with.

Apple will likely come with a M2, MX or whatever which will crush the remaining x86 desktop competition.

As for hybrid solutions? Who would want that? When has hybrid solutions worked EVER in tech? You simply increase cost and create a jack of all trades master of none. It is like a hybrid electric. Almost same price as an EV but with none of the benefits like simplicity, more storage space etc.