My Dad is 81 and has really been going downhill for the last couple years, maybe since Covid. Prior to Covid, when I guess he was in his mid to late 70s, he would go out for cycles up to 30 miles with friends once a week. He had no real problems driving, and he and my mom socialized with friends regularly.
Now, he's losing his vision and hearing, which makes it tough for him to ride his bike. He will still ride up to 5 miles around the neighborhood but that's way less than he did before. He is a marginal driver, probably shouldn't be driving honestly. He has trouble reading and using a computer due to his vision. I have also noticed significant mental deterioration in the last five years. I think loss of hearing is really contributing to this. After Covid, my parents never resumed socializing with their friends. He also suffered some serious side effects after having a hip replacement.
My mom is six years younger and still doing OK.
My MIL is in her mid 80s and also has deteriorated hugely in the last 5 years, since Covid. She is barely able to live on her own.
On a side note, it is just crazy to me to have presidents and senators over age 75. Just totally batty.