Hi! Do you have sources about this fact ?
This article sums it up pretty well. Most developers dont know that the default is insecure.
Only fsynced is the option that garatuees writes. But then MongoDB does not have performance benefits. There are other NoSQL DBs that are better and For Payment data I would always use a RDBMS.
Wow this article is very interesting ! Glad to know that now :)
Thanks a lot for your sharing