YAML is kind of like C++:
> You like C++ because you're only using 20% of it. And that's fine, everyone only uses 20% of C++, the problem is that everyone uses a different 20% :)
https://eli.thegreenplace.net/2009/10/17/the-c-bashing-seaso...
The YAML footguns are too numerous to reproduce here, so here are some sources:
https://stackoverflow.com/questions/3790454/how-do-i-break-a...
https://www.arp242.net/yaml-config.html
YAML isn't terrible if you only ever have to read what you wrote. Now consider that there are 63 different ways to write multi-line strings in YAML -- how many of those have you committed to memory? Yeah... now throw 10-100 developers into the mix, each with their own favorite alternative syntaxes -- good luck making sense of your YAML.