Should I fix my six-year-old laptop or replace it?

Pablo asks if it's worth patching up an old ThinkPad T510 or best to buy a new Windows 10 laptop I have a Lenovo ThinkPad T510 purchased about six years ago. I'm perfectly happy with it, except the keyboard needs replacing and batteries seem to lose their ability to charge within a couple of years. The keyboard and battery could be replaced for less than $100. Other than those factors, is there any reason to replace the machine? If I buy a Windows 10 machine, could I or should I continue to run ...