> with 0 install
Well, that is somewhat incorrect; unless you already have it installed, npx will download prettier and do a temporal installation.
So, if you DON'T have prettier installed locally on your project or globally, and then you try to execute it with the --no-install flag (so it actually doesn't install anything), like this:
:%! npx -q --no-install prettier
It will fail.
Installing it globally perhaps would be better. Otherwise you are downloading prettier over and over each time you try to format your code (and by not having to download it, the command will be executed faster).
Totally true, but the whole point of using `npx` is to stop thinking about if it's installed or not. As you pointed out it will be installed temporally, the huge benefit is that it's abstracted for you and from you, you might always run the latest this way but if you want to have it actually installed it's a easy as running:
:%! prettier
😀