All these comments amuse me, because I feel the opposite. YAML has always made immediate intuitive sense to me. Meanwhile TOML feels like a terrible hack.

Also, I'm guessing I'm in a tiny minority who loves YAML but hates Python's semantic indentation...

I like YAML but it has some minor quirks and it feels overused in domains in which it simply doesn't make sense to use YAML. I can think of ansible or complex dynamic configurations that depend on external values as mentioned in the article. If simple merging of a base file + dev, staging, prod files isn't enough for the task at hand then YAML is a bad fit.

I'm the same way. I think it's a difference in my expectations of a programming language versus a hierarchical data storage format. I'm fine with (and even prefer) enforced whitespace in data formats. That makes it easier to view and edit.

In programming languages, it makes me twitch. I don't have any problem with "accepted" formatting styles (i.e. linux kernel c style), but for the language itself to enforce that for some reason feels like it's adding perpetual cognitive overhead (like whenever I use python). I don't know why; it shouldn't be any different than using a particular formatting style voluntarily in a more flexible language, but somehow, it feels different.

This is strange. The thing I most like about YAML is how intuitive and human readable it is.

One thing that is rarely pointed is that one of the advantages of TOML is that it allows to write dictionaries/tables not as trees.

Agreed. From readability perspective, I started out with INI, which I ditched partially due to having no standard on the format and skipped JSON when it can't add comments, skipped YAML for not looking too intuitive, considered JSON5 but skipped for being not popular enough and landed on TOML.

And I skipped toml for an object-array syntax that makes baby Jesus cry.

None of these problems are hard, why are all the solutions so awful?

What are you using now?

XML, generally. I hate it but I've given up on its "successors".

Hocon for me, if I get to choose.