>Failure to collect trash under certain conditions is not a failure of a trash collecting system.
Of course it is. If your phone fails to make calls under certain conditions, that is a failure of the system, and we try to fix it (for example by deploying more antennas, or by fixing software bugs in it).
If workers refuse to pick up trash, we can also fix that (ask Ronald Reagan).
There's no expectation of continuous (24/7) trash pickup, unlike your phone where (these days) you expect it to work all the time.
If the regular collection schedule is every 7 days, and it turns into 14 or even 21, for the most part your trash is still being collected within the bounds of "yeah, my trash gets collected".
Failure to collect trash under certain conditions is not a failure of a trash collecting system.
Inability to regularly collect trash is the failure mode we're concerned about.