The RAF fitted 2 collision avoidance systems because of the nature of modern ‘Safety Systems’ - the management kind, not the technical kind. Once you have identified something that ‘might’ be a safety enhancement, it is a brave sole that stands up and says you don’t need it.
Its also a light aircraft. There are a myriad of COTS replacements for any instrument that is obsolescent. Despite the best efforts of the RAF to make it difficult, it’s a simple aircraft to operate, has plenty of life and is relatively cheap to operate. I’m not sure why you seem to think otherwise BP?
You May also wish to research the airworthiness issues the Chipmunk had in its lifetime - spinning for example! Chipmunk Aeros were the same as the Tutor is now - I flew both.