FrogReaver
The most respectful and polite poster ever
In my experience it’s very much the case.
There is a difference between hard and requiring more time.
And if the DM leaves, no more game. If you’re lucky, you might have a player who can step up, but it’s far from a given.
If the DM leaves then one of the players becomes the DM. I'm not sure why you think that requires luck or will not be the typical case.