We vacation every summer with my Mon who is now 79. At home. she can walk short distances Ok but uses a cane whenever leaving the house. She doesn't use any other helping device at home. But, at WDW where there is just so much walking, we always get her a wheel chair. We get the multiday one at the parks so she is pretty much in the wheelchair most of the day, though she has no trouble transferring out for rides, restaurants and stores. She walks around the resort with her cane and beings her cane with her to help to get from the buses to the park (sometimes there are free wheel chairs for this purpose but you can't count on it).
My mom has zero interest in a scooter. She doesn't have experience driving one and learning in a crowded place like WDW is not something she wants to do. My daughter was run over a few years back by some guy in a scooter who didn't even apologize or look back after he hit her. His wife was running after him yelling "You just hit a kid!" and he still didn't slow down. That has given us all a pretty bad feeling about scooters.