Yup! You can actually render jupyter notebooks into quarto outputs. I like Quarto better than Jupyter because it's a lot easier to version control .qmd files.
(disclosure: I'm a Quarto dev) You can also render _to_ Jupyter notebooks from .qmd files, in case that would be useful for your workflow. We've put a lot of effort into making Jupyter interop a good experience in Quarto, for folks in either the Knitr or Jupyter ecosystem.
Quarto is pretty different from Rmarkdown because it doesn't require an R runtime. This opens up a lot of possibilities when you don't want to include the R dependency.
One of the things I really love about Quarto is that it's a great way to package WebAssembly tools. For example the Shiny for Python website is built using Quarto and has tons of WASM examples which let people play around with the framework without having to install it. It's really changed how we write documentation.
The main benefit is that you get a Python (or R, Julia or Rust) interpreter. So you can evaluate code. A good example of the value of this is the Ibis docs which use Quarto: https://ibis-project.org/