I'm soooo far away from my golden years I haven't given it much thought.....
The idea of a wonderful travel companion (civie world) sounds great. But I've learned in my travels that the ideal travel companion may well be very different than your wife, SO, or even platonic friends.
There is
a lot of "together" time, often with it impractical to meaningfully "get some space." You need to have similar interests, pace, balance between "taking it easy" & adventure/exploration.
There are a number of people in my life that I love dearly but hate to travel with....