This _so_ much. Where in the past I've used Jupyter Notebooks for short, one off stuff or to test something, I now do that online for almost any language.
Notebooks are still useful to write documentation though.
Web playgrounds are ok for testing some syntax (if you don't have a local REPL/easy way to test), but not for one-off stuff that involves file input or that you want to check against real environment assets.
I know, but that's what I had used it for too. Like posting some code, for example in a HN post ;) As I've said, I still use it mainly for documentation.
Unfortunately, my relationship with Mathematica didn’t go anywhere: It was too expensive back then, and I never found a good use for it except for double-checking my homework.
I tried other computer algebra systems, but they didn’t impress me as much.
If you own a Mathematica license and found a good application for it, please let me know!