I'm in awe of those that ride 5-10 thousand a year into their 70's and 80's. It has to end though and it should not mean that you're not among the most fit for your age group. If you rode 2K per year, a drop for some, would your heart rate rise, BP, cholesterol? I think not. Any Doctor would tell you that 10 hours of hard exertion weekly is great.

FWIW, I'm 67 and ride every other day for 30-40 miles, about 2500 miles yearly. . I could do more, but I've an older house to work on, a wood shop, a boat,like to hike, gardens etc. Those are things I love. Just saying that if you can't keep up with those you used to, adding other interests to the mix might be an alternative. I've had a goal the past 15 years of riding a century on or around my birthday (July), I gear up for it and grit it out solo.. Then I'm free to enjoy the rest of the summer with lite riding until the fall when it is just spectacular here and I ride hard for another 2 months.

Might be time to relax a bit, you've earned it.