I don't understand why this is a problem at all. AFAIK macOS is UNIX, so you can create user accounts and run programs as separate users. This is what I routinely do on Linux to run coding tools or other programs that should not have "full disk access," in particular to the files and mounts of my main user.
Imagine having a personal assistant paid by a sketchy surveillance company. They can't do personal assistant stuff without full access to your email, calendar, etc., but the company paying them wants to harvest your personal data.
Personal assistants are realistic for very rich people because they can be paid an extravagant wage and punished for disloyalty. A personal assistant costing pennies to someone else, with access to data worth more than its salary, makes no sense.
Yup. I do this all the time on both Mac and Linux.