Coffee in moderation is healthy for you and can help your heart health and reduce the risk of heart disease, heart attacks, strokes etc.
Drinking coffee in moderation should not cause any problems with your kidneys and it's been said that drinking more than 5 cups of coffee per day increases your risk of kidney disease.
However there's been no medical evidence or research that shows that drinking too much coffee causes any kidney problems or kidney disease.
My grandma lived to be 110 and she drank sometimes 24 cups of coffee per day and she had no kidney issues or kidney disease.
So it may just be certain people that get kidney issues from too much coffee or it may not be the coffee at all that causes kidney disease.
The kidney disease might be caused by something else entirely.
I drink around 7 cups of coffee per day and my kidneys are very healthy as of now.