Google does not deny that developers of Gmail add-ons can read emails
The other way around, it also seems hard to make it hard for a developer to have ‘self’ access to your email. , or that this is only an automated system where nothing is stored (such as Grammarly and associates). How does an add-on work that allows you to insert smilies quickly? Or a disguised ‘advertising add-on’ that uses your email for targeted advertising?
I think it is too simple to say ‘but you gave permission’, I dare to say that 90% never read conditions or privacy rules, but secondary, disagree = can not use.