I think we're generally overconfident in our prognostication 10 years out. We make assumptions about RO in the future using current knowledge of, say, radiology in the present. But clearly when radiology was decreasing in competitiveness 5-10 years ago, people didn't know what the future would hold. If they did, it would have remained competitive throughout. Did we know that immunotherapy and targeted therapies were going to make med onc super competitive, or that IMRT was going to make rad onc super competitive before they happened? Not that I know of.
I think there's too much uncertainty to say for sure that field A is a good bet vs. field B. Will med onc still be lucrative once immunotherapy drugs become generic in 10 years? I suppose that will depend on its advancements in the interim.
I would say that radiation oncology technology is moving at a pretty fast clip and we're better at immobilization and targeting than 5-10 years ago.
Ablating oligometastatic disease is a pretty awesome concept now, and I think it's becoming more widely accepted that it's effective.
Similarly to radiology, RO is also procedure-based and generates revenue for hospital. That should be a good bet.
My honest opinion is that if you see yourself as a multidisciplinary oncologist and not a technician, you will be OK.
You probably shouldn't expect amazing reimbursements back 2000s when IMRT was exploding, but I think it's a very rewarding career. We have a very strong role to play for increasing survival in both local and (increasingly) metastatic disease.