About your bone death or osteoradionecrosis, that section of bone will rot and of course you are right, it must be removed. However, the bone died from lack of blood supply and that is usually not limited to only the area where the teeth are anchored. Removal of the dead bone without a viable replacement of bone is like building a house on a crumbling foundation, it won’t last long.
The alternative is to have the bone section replaced with a transplant from your own body. Not just the bone but the blood supply tissue known as “free flap”, which is carefully connected to a good artery supply. Once healed, a prosthetic teeth group can be installed.
Sorry but your dentist does not get the new luxury car because health insurance usually covers a good portion of this.
This operation is performed only in limited hospitals and clinics because it requires study and set up time and is a unique surgery. You can investigate this on your own, typically limited to the mandible or lower jaw bone and is known as a mandiblectomy with fibula free flap. The bone typically is harvested from your leg fibula bone, a non-weight bearing bone. Or it can be harvested from the shoulder, collar bone, pelvis bone edge, or other places.
The upper jaw requires other options. Perhaps you should talk with someone other than your dentist.
I had this done at Mayo Clinic Rochester over four years ago. I can easily eat corn on the cob, steak, or almost anything now.
Is your issue with both upper and lower teeth? Both sides? Do you live near a large medical facility or can you travel to one?