They're not without their drawbacks, like no official standards etc, but they do their job well.
I will be bookmarking this like I have the ini critique of toml: https://github.com/madmurphy/libconfini/wiki/An-INI-critique...
I think the first line of the toml critique applies to CSV: it's a federation of dialects.
Until I worked quite a bit with them and realized that there's always schema in the data, otherwise it's just random noise. The question is who maintains the schema, you or a dbms.
Re. formats -- the usefulness comes from features (like format enforcing). E.g. you may skip .ini at all and just go with lines on text files, but somewhere you still need to convert those lines to your data, there's no way around it, the question is who's going to do that (and report sane error messages).
My experience has indicated the exact opposite. CSVs are the only "structured" format nobody can claim to parse 100% (ok probably not true thinking about html etc, just take this as hyperbole.) Just use a well-specified format and save your brain-cells.
Occasionally, we must work with people who can only export to csv. This does not imply csv is a reasonable way to represent data compared to other options.
You don't need to though since in most cases you just need to support whatever CSV format the tool you're handling, unless of course you're trying to write the next Excel/Google Sheets competitor.