CUE works with all of those languages, so it doesn't matter what the tools or others are using. I can always apply CUE at any point to output their required format as needed.
Keep your legacy config and mess if you want, you're the one missing out
Also, I don't see TOML in the wild enough and the others have been around long enough, I must chuckle and not take seriously these claims about "inertia"
I’m not claiming inertia makes TOML ‘best’, just that it’s clearly not blocked by inertia either. Cargo standardized on TOML years ago, and GitLab Runner has relied on it for a long time. If a format can win in major ecosystems, “people won’t adopt anything new” isn’t the whole story.”