Hi, OP here. Perhaps "minimal barriers" would have been more accurate. One of the problems we want to solve is the proliferation of bot traffic on job sites. Requiring a Google login is the simplest way to achieve this for the time being.
If you really want to keep the login then maybe a message like we won't spam email you unless asked and only want your to log in to protect against bots would help.
Such messages are lies usually in my experience.