Yes it is a poor choice for a cut off. I am 70, have all my own teeth, don't drink vodka, have regular eye exams paid for through socialized medicine every six months, can't think of any downsides. Oh, yes, have all of my faculties, cause still work full time in healthcare.
The cut off in Ontario is 80, then you get called in by the DMV to do written test. Do, I think I have made a point here.
Also, 70 is not considered OLD any longer, and I hope most of you reach it!