I think Apple will keep selling x86 Macs forever. For heavy-duty workstation workloads, M1 just doesn't cut it.
Apple immediately discontinued all Mac minis, almost all the Macbook Air and Pro line ups and the iMac's running Intel. The last form factor to transition is the Mac Pro.
> For heavy-duty workstation workloads, M1 just doesn't cut it.
Perhaps you are right on this one for now. The M1 doesn't cut it for 'Apple's standards' for now but when the time comes for the Mac Pro to transition, it won't use an M1 chip, but probably an M2 / M3 chip.
Apple Silicon is the start of it all and M1 is only the beginning and is certainly not the last. So its worth waiting to see how the M1X, M2 or M3 Macs improve over M1.