Can you explain why comments in config files have no real value?!

Have you never commented out part of a config file temporarily? Have you never wanted to make a note to yourself in a config file to explain why you set it that way?

> TOML just seems like a re-invention of XML

I think you must be confused. TOML does not in any way look like XML, nor does it have the same features.

In the Python community, it is gaining traction very fast. The standard file for configuring your project is in fact pyproject.toml.