It includes protection from forced retirement, although there are limits around this sort of thing.
Most of the retired academics I have known saw retirement as a responsible act, in order to provide opportunities for newer researchers, even if they felt they could have carried on themselves.
This obviously does not apply to Oxford professors, but in the US it is illegal to discriminate against anyone over 40 based on age.
https://en.wikipedia.org/wiki/Age_Discrimination_in_Employment_Act_of_1967
It includes protection from forced retirement, although there are limits around this sort of thing.
Most of the retired academics I have known saw retirement as a responsible act, in order to provide opportunities for newer researchers, even if they felt they could have carried on themselves.