I think it all depends if they are healthy enough and if their foot pain limits activities. Many seniors are active and want to be pain free. Nothing worse than having foot pain later in life. If all the over 70 year olds did not have foot surgery, a lot of podiatrists would starve.
I do believe patients should try conservative treatments such as callus pads, bunion cushions and hammertoe protectors first before foot surgery.
Teri Green Atlas Biomechanics