With logic operating at such low voltage, the current you have to supply to the die is very high even in "low power" chips, and you begin suffering significant copper losses over single millimetres.
If you can put a DC-DC converter on the chip itself, that problem is solved.
Well is talk about DC-DC being made along with logic or with a separate analog process?
With the second, chip scale bucks were certainly made.
GaN grows on Si nicely, and ferrite-on-si is also a thing.
GaN on Si could work, as could ferrite based inductors, but at least for the foreseeable future it doesn't seem like the incentive is enough to make it a wide scale thing. Probably heterogeneous integration stuff like say maybe chiplets, flip chip bonding, etc. might be the route if GaN converters get integrated.
They still use FIVRs on mobile chips, except they managed to put inductors in the substrate now
https://www.psma.com/sites/default/files/uploads/tech-forums...
What Intel was saying is that they had an on-die industrors ready in labs, but never stated if they are going into production.