Part of the standard configuration for fields, even for sites that don't have content translation enabled, is whether or not an instance of a field on a particular bundle is translatable. This means that recipes which define content types are providing opinions on which fields are translatable, so we should develop a policy so that the opinions are consistent and follow a considered approach.
Only field types which contain text (e.g. title, body, summary, etc) should be translatable. Field types which contain other kinds of data (images, numbers, dates, entity references, etc) should not be translatable.
Active
General
This is already covered in 📌 Track 17: Multilingual Roadmap Active , but no issue documenting it separately I guess?
Don't think there was any disagreement on this so marking it fixed, thanks @mandclu!