I am switching from Rmarkdown to Quarto and have encountered a wired behaviour:

Here is a simple example. When I render it, the inline R code Sys.Date() is not executed.

---
title: "Untitled"
format: html
---

Today is `r Sys.Date()`.

But as long as there is an R code chunk (even if it is empty), the inline R code will be executed:

Or, as #4855 suggested, by adding engine: knitr in the YAML part, it also works:

It’s a bit confusing for someone who just switched from RMarkdown to Quarto. Can someone explain why this happens? Many thanks.