Whenever I have indoor Photopass Pictures taken, I ask them specifically to check and make sure the flash worked. When those batteries wear down at an end of shift, they don't recharge fast enough for the number of pics those park photographers are taking. I can't recall ever having had pictures that bad ... but the Photopass photographers clearly vary WIDELY in both ability and interest.
I used to lug my DSLR around the parks, but I rarely do anymore - it's a lot of work. Best investment I ever made, though, was buying a really good new Point and Shoot (a Canon G7x MkII). It takes fabulous pictures and videos, is infinitely more flexible than a phone camera, and doesn't drain a cell battery. If we do a character stop, regardless of whether we get a photo pass, we're taking pictures with that as well. The results are spectacular, even on auto setting.