For instance the baby sitter you hire now and then probably keeps track of the contacts of their potential clients, and you could request deletion of your data if you don’t intend to work with them for a few years.
> 2. This Regulation does not apply to the processing of personal data:
> (c) by a natural person in the course of a purely personal or household activity
My sense (I am neither a lawyer nor European so this is certainly not European legal advice) is that you cannot use GDPR to compel someone to delete your contact info if they're solely a social acquaintance, but you can use it to compel them to delete it if they're a one-person business of some sort (contractor, Etsy seller, lawyer, etc.).
The person you traded phone at the bar last week, your neighbor or your coworker from last job are not.
1) if your data is processed for contractual purposes, the data processor has a right not to delete it on request
2) if your data is processed for law enforcement purposes, the data processor has a duty not to delete it on request
There are several legal grounds for processing personal data under GDPR, and consent is only one of them. I think most of the others outweigh any request for deletion by the data subject.
E.g. if some law requires a company to retain certain data for longer periods than stated in GDPR, that law still applies.