I found PDF SAM basic ("split and merge") well done: https://pdfsam.org/en/pdfsam-basic/. That one is open-source and multi-platform, they have more features in a paying superset project.
i've tried 'pdfcpu images list' on a random pdf i've had lying around and the tool unexpectedly started downloading some font from unspecified internet location to my local disk.
I had to bash my head against the wall and submit myself to paying for a creative cloud license. At least acrobat just works. Although I wish there was a reasonable alternative.
That said, if you're looking for a GUI app to do simple PDF mutations it's often hard to fine a simple solid open source cross platform app.
At least I haven't found one :)