For years, I have been using different watch faces depending on the time of day and if I am at work or not. The complications reflect the use cases witch of course are totally different when I am at home, hiking or at work.
I was not aware of the possibility to change watch faces automatically at a certain time or even at a certain place with WatchOS 7.
AppleInsider has published an article dealing with this option using shortcuts. It looks very interesting.
If you already knew about that, sorry. I never would have expected to have this automation going on. Sure, changing watch faces by swiping to the left or to the right is not tedious at all. But automation is always nice.