But they're not asking for your consent for that. They're saying that if you use these features, they have a legal basis (legitimate interest) other than conse

But they're not asking for your consent for that. They're saying that if you use these features, they have a legal basis (legitimate interest) other than consent to use your data for product improvements. The only thing they're asking for consent is for providing the features. Which you appear to want to use, and which genuinely can't be provided without access to the data, so where is the problem? (I don't think it is as unbounded as you claim. They'd still be limited by their other policies, which for Workspace are quite restrictive, and by what EU DPAs would actually find reasonable to be covered by legitimate interest. It is not a free ticket to do anything you want.)