JSON is too small (no comments) and YAML is too big (many string syntaxes, relatively few implementations).
TOML is in the sweet spot for complexity, but I agree this syntax is by far the most confusing part.
TOML 1.1 improves it at least:
miniblog.
Related Posts
"Minus 100 points", an article on deciding how to add features C#, remains one of the best introduction to PL design principles I've seen: https://docs.microsoft.com/en-us/archive/blogs/ericgu/minus-100-points
(Design is hard, combinatorial complexity grows easily, saying "no" needs to be a default.)
1
Writing a REPL that evaluates-as-you-type, keeping the UI responsive and staying defensive against runaway memory usage: https://scattered-thoughts.net/writing/making-live-repls-behave/
It's a really hard problem for PLs, but even this small live demo has a lot of complexity.
The computational complexity of the Apollo 11 computer versus a USB-C charger today!