Okay, I overreacted.
Not everyone leaves.
A lot of people leave,
But then people you consider "better" come in and take their place.
That is, until they fuck up, and you're crying your eyes out wondering if "better" was ever really better at all.
Rinse and repeat.
It sucks, but it's life, and life really is all we have.
So it doesn't make sense to mope about everything,
or to get caught up in every single detail,
because then you're just wasting the only thing you have.