Here is a good example of the problem with a growing number of octogenarians in the U.S. federal government:
https://reason.com/2024/12/23/kay-granger-like-joe-biden-is-a-symptom-of-americas-gerontocracy/?utm_medium=reason_email&utm_source=new_at_reason&utm_campaign=reason_brand&utm_content=A Decaying Joe Biden Underlines the Need for a Less Powerful Presidency]
It's all about holding on to power in the U.S. Congress, not actually representing your constituents.