Universaly understood binary file formats, DFDL & SQLite

I want to program weak embedded devices, so I want to use binary files as input data. So there is no need for expensive complicated parsing. Meaning: No Text-Files of any kind (XML, JSON, etc.).
But XML & JSON have been such a huge success because they're kind of self-documenting and easy to read - by humans. Still: Like Garbage Collection, this comfort doesn't come for free. One of the reasons Rust exists: You can't just always ignore Garbage Collection as "it's not thaaat expensive".

But the only way to document a binary file-format in a standardized way I know is DFDL. Where is no big support in Rust and in general. I tried a whole day to get a good workflow with DFDL, but couldn't, and I still miss good IDE support.

I then thought: What binary data format is (almost) universally supported, in almost every programming language? Answer: SQLite. Think about it:

  • High efficiency in reading and writing. But: The SQL text-to-binary parser doesn't come for free, maybe that's killing it?
  • Reasonable file sizes, only a little bit wasteful. I only wouldn't want it in the weakest embedded devices.
  • The whole database is in one file!
  • Constantly maintained support for every major programming language I can think of.
  • Sea of tools to read and write it.
  • Works w/o server.
  • Easily extendable format.
  • While mostly an efficient binary format, still self-documenting through table-names, column-names, constraints, data-types and relations.

But still: While it fits all my criteria, it doesn't feel right to use a DB for that. So, if you see flaws in my thoughts, please, tell me what they are and sell me a better solution.