Earlier quoted context omitted.
That's my favorite thing about all these services. None of them have an equivalent of a stop-loss. They'll notify you IF you setup an alert, but that's it. Often times the alerts are way after the damage is done, with some billable metrics often lagging in reporting/alerting by hours. The default should be safe with easy options to increase the limits.
I remember trying AWS Glacier as a broke university student, thinking it was a cheap way to back up my data. I was wrong. A decade later I played around with AWS, set up a free 1-core VPS. It was fine for a year or so (I ended up not using it at all), and suddenly I got a bill. It wasn't much, but it reminded me how these services make it very hard to be aware of your bills until you get them. I was trying out Azure…
It's not cheap to restore though, at about $90 minimum per TB.
So it's best as part of a 3-2-1 system, not for frequent restores.