Cases when Time Machine can't provide one with backup data

[Mac2013orlater]

Let's list all cases/situations when the Time Machine can't provide
you with a backup of your data. Just to be sure my understanding
of TM capabilities and its properties is fine. Only this way the decisions
regarding using TM and eventually extending the backup plan with
additional solution can be right.
I kindly ask you to give a feedback if the summary is correct,
or if any situation/case is missing on the list.

* The free space of storage used for backups runs out.
Well, this is a generic problem of limited storage space resources
each backup solution will be affected by. So, it does not seem
to be TM specific problem.
* As soon as the original file/folder was removed intentionally,
or unintentionally by any mistake or other there is no guarantee any
more the TM will keep a backup of the item on the backup storage.

 

[PeterJP]

Let's list all cases/situations when the Time Machine can't provide
you with a backup of your data.

When there's a problem. For example, I recently got a warning that, for reliability reasons, Time Machine should make a new backup. It turns out to be a frequent problem when backing up over Wi-Fi, even to official Apple Time Capsules.

I won't detail it here, because it's OT in this thread. I'll make a new thread about it.

 

[ScoobyMcDoo]

The backup is on-site, so in the case of fire, earthquake, etc, all copies of your data could be destroyed.

 

[Mac2013orlater]

The backup is on-site, so in the case of fire, earthquake, etc, all copies of your data could be destroyed.

That's true! However, I kindly ask all participate to address in this discussion
the only TM internal issues. It will help to keep the discussion smooth as possible.
If TM external factors need also such discussion a dedicated thread can be started at any time. Thank you!