Earlier this month, @idavydov filed an issue against Quarto reporting that it is about 100x slower than rmarkdown for documents with long output. The minimal reprex was striking:
cat(strrep("x\n", 100000))
Running quarto render on a document with that single chunk took 35 seconds. The equivalent rmarkdown::render() finished in under half a second. As a side note in the issue, the reporter pinged me …