I use Gnome-Photos, only for my online albums as it works closely with Online Accounts. If other people use it that way, they’re probably not pleased, like me.
Unfortunately, Gnome-Photos is extremely slow in loading online content, and it has to be reloaded each time it’s invoked.
For the few photos I keep locally, Shotwell is what I use. It has far more features, and a very important one that I can’t do without - Tagging.
Whatever is decided, I’ll be happy as long as Shotwell is available for download, and that Gnome-Photos improves its loading times for remote photo-albums.
So as to what’s the default, no worries personally, as long as I can download whatever I need from the repos.