The vast majority of library documentation of even major libraries is simply text with no playground. The fact that they’ve made the effort to add a playground

The vast majority of library documentation of even major libraries is simply text with no playground. The fact that they’ve made the effort to add a playground by leveraging a fairly easy to use tech should not be held against the open source maintainers! Besides, all those examples are trivially reproducible locally, the way you would have to do it for the vast majority of languages which don’t give such fancy interactivity in their tutorials.