Google archives data off after 18 months. There’s no telling how long that data is archived. In the healthcare industry, there’s a 7 year mandatory archival period, but having worked in healthcare IT, I can tell you that they keep that data for MUCH longer than 7 years.
I would guess once you’re out there, there’s always going to be a record of you somewhere in some archive. Storage is cheap, and corporations are paranoid.
FDA regs determine how long the data and documents are kept and you are right some stuff never is destroyed.