Google forms is not anonymous. it's just not.
*you* might not be able to see who answered your form. but Google can. any person who forgets to open the form in incognito now has the form tied to their shadow profile. if they have a Google account, now it's tied to that account, i.e. likely tied to their legal name.
and forms answers are not encrypted. Google can read every single one.
a form on Google means 90% of respondants sign their response with their name, address and place of work.