I seem to remember another Mac user with difficulties with eos-installer, /e/OS Installer unable to install /e/OS on Fairphone 4 - #4 by senneonair
Mac is not very accommodating with cross platform work.
The SDK link within the /e/ documentation does have a Mac (darwin) download. Again perhaps not so easy on a Mac but it can be done. The unzipped executables need to go to Applications, will not work in Downloads I have read.