https://peps.python.org/pep-0723/ is an ecosystem-wide standard first proposed over 2 years ago, before any of the big names in Python packaging discussion showed any awareness of Astral even existing. They are not "uv scripts".

There was also a competing PEP 722; this was simpler and more natural reading, and my personal preference, but ultimately the community consensus preferred the extensible TOML-based format. The author of that proposal explicitly rejected doing things the way you chose to; you may agree or disagree with the reasoning — https://peps.python.org/pep-0722/#why-not-use-a-marker-per-l....