My PCP, who is about 69-70, has been scaling back for the past few years. When I started with her in 2005ish she worked 6 days a week for most of the year. Nowadays, she closes every Friday and works every other Saturday for 7 or 8 months of the year. In the summer, she just works Tue/Wed/Thu. Further, she takes several vacations throughout the year now.
I worked at a place in the 90s for eight years. They must have changed insurance carriers 3-4 times during that period, so I had to change PCPs a lot. When I started the job I have now in 1999, I was able to keep the same insurance carrier. I kept them because I didn't want to change PCPs again. I changed in 2001 because the one I had before I refer to as Dr. Evil B**ch. I plan on retiring in 2021; will keep the same insurance until Medicare age in 2022, but I realize that I will probably have to change before then and maybe again afterward.
C'est la vie!
Edited to add my dentist retired a few years ago. He sold his practice to a larger, more modern one and worked a decreasing number of days for a few years until he finally quit 2-3 years ago. The new guys aren't exactly youngsters, but this practice is a lot more "corporate" for lack of a better word. Good dentists, however but the "homey-ness" is gone.
Have lost a few doctors due to insurance issues including my favorite PCP of all time, the one I went to in 2001. She referred me to my current doctor.