Why is home dialysis 6 days per week, whereas at a dialysis center it is only 3 times per week?

Home Hemodialysis. Your kidneys work 24 hours a day 7 days a week. More frequent dialysis has multiple benefits related to blood pressure, anemia, metabolic bone disease, quality of life, libido etc... Take advantage of the more frequent dialysis. You will feel better.
Important question! Kidneys function 24 hours a day, 7 days a week. So it sure seems reasonable that the more dialysis one gets, the better. Home hemodialysis treatments are usually a little shorter than in-center treatments, but it is possible to do overnight home dialysis - running at a slower, more gentle blood flow rate. Home peritoneal dialysis, of course, must be done daily. LGromkoMD.
Time. If you can do home dialysis, you can do it more often because you have the machine. Going to a center means you have to share the machine and have to use it at specific times. More sessions of dialysis are almost always better.