Sometimes, say if you go on vacation to someplace 900 miles away, for me that is Northern Michigan, and you are taking wife, kids, four dogs, the only way that I can also take a bike is trailering.
I almost never trailer anywhere. But.... I trailered to Ft Collins, CO (from central IL.) a few years ago to, as we said, "Get through the corn". Then did a loop down through CO, AZ, UT, NV, CA, OR, WA, MT, WY and back to CO.
Cracks me up how folks who are NOT trailering want to bum a spot is your trailer for all manner of crap! Musta had 1000 lbs of other peeps stuff along!!