[bombcar]

To be fair, that limit is 80 and likely has more to do with not forcing elderly Cardinals to travel (many would and even still do out of a feeling of duty; it's basically literally the only "job" a Cardinal has that's not just him being a bishop).

[telotortium]

Currently, bishops are generally expected to submit their resignation to the pope upon turning 75 years old, although the pope may elect to retain the bishop.