Google's Firebase has had some absolute horror stories, especially when Firebase found out they were under-billing some people and then "adjusted" their bill to be more accurate, causing massive charges.

Just two stories on HN I've seen about it:

2017: https://news.ycombinator.com/item?id=14356409

2018: https://news.ycombinator.com/item?id=17661391

I have nothing against GCP or Firebase, just countering the "this seems to be unique to Amazon" comment.