From what I can tell, Quarto is essentially an installer for Knitr/R, that also comes with a bunch of goodies, like when working in VSC (or Rstudio) it auto-suggests cross-references to content in the document, like figures/chapters/equations/etc. It also has a github action that builds and deploys the site in like 1 one line. Just removing the friction and lowering the bar is very helpful sometimes.
That's true, but quarto also has full support for Python and Jupyter notebooks, not to mention julia, and observable. It's really built from the ground up to be multi-language so that everyone can benefit from all the goodies in RMarkdown.
