It depends on the particular job, of course, but generally speaking, yes, many jobs no longer have physically demanding tasks, which allows older people to be able to work these jobs. People live longer, and those who take care of themselves remain strong and able to work past the current retirement age.
The minimum retirement age shouldn't be determined by how many years of labor we can milk out of each person. People look forward to a few years of freedom after a lifetime of toil in their dismal cubicles. Let people have five or six years of joy at the end of their lives, before full decrepitude sets in.