Did you read the Canon precaution statement in the link that you provided, about certain Camera models will use the older EOS v2.1.4 utility even when the EOS 3.12.10 utility is installed? If this is the case for your camera model, then the question rises whether EOS v2.1.4 is even compatible with the version of macOS that you have installed. Is there firmware available for your Canon camera that you have not installed yet?
Canon is solely responsible for every aspect of their software, drivers, and firmware compatibility with the intended operating systems that they list as supported for their product version's System Requirements. Apple has nothing to do with Canon's product development, or support.