My experience has been that many experienced clinical non-procedural positions (FM, IM, EM, etc) make same or similar to first 1-2 year rad onc in my competitive metro (academic or not).
Mid career rad onc will typically make more than those non-procedural docs. After a few years rad onc pay should increase, though in competitive metro this requires hard renegotiation or a move out to greener pastures elsewhere in the country, rarely in area. Some rad oncs are unable to successfully renegotiate or move, and they get exploited. Other specialties much easier to stay in area and jump across employers if there are difficulties. Your mileage/pay my vary in academics... What even is academics anymore. It's such a spread from very research oriented to basically an employed clinician. Very academic positions may continue to pay mid-career non-procedural rates.
This is excluding the very low rad onc pay you hear about from places like Harvard, Stanford, Hopkins, Penn, etc... First year family practice at a public community health center makes more than instructors at these places to my knowledge.