This is kinda absolute BS at this point, though.
Mongo has acid transactions, and has for years now. Although this is only within the same database, there are plenty of dbms (including rdbms) that don’t support cross-database transactions.
Mongo also, since time immemorial, has had “write concern” to ensure that it’s written to disk (to the journal) before the transaction is completed.
Yes, ish. There are aspects of it that are really valuable, and fit some use cases extremely well. But, in some senses, yes. Like any DBMS, you’ve got to know it’s strengths and weaknesses. And if you do, there are definitely circumstances where you’d choose it over others. But not always.