Just before they were removed, I decided to eliminate all of my Rules and Modes entirely, because they were turning out to be extremely unreliable, and there was a bug whereby the Pixel went back into DND mode after a restart, even when it had already been moved outside of the location. It was also quite unpredictable how any Mode would behave, when there were all kinds of settings for each one, and it was just too much to set up and keep track of.
Today, DND is even more onerous. In the Clock app's Alarms tab, if DND is enabled, the app prevents me from editing or deleting or modifying, in any way, the alarms as they are set. This is terrible. You see, Google really, really wants us to disable DND and keep it off forever. DND is very bad for Android. So they are making it as inconvenient as all-get-out to leave DND enabled. If it were up to me, I'd leave it defaulted to "on" until I wanted to be disturbed.
It would be unfortunate for them to phone you precisely in the small period where DND was turned on as you walked past the opera house (even a large one would be, what, under two minutes of walking?) and not try you again.
(Because if you have instant location-based DND, yes, it might turn on as you walk by an opera house but equally it would turn off when you were past the opera house. Normally, though, I'd expect location-based DND to only kick in after a certain period of time in the same location - say 10 minutes.)