The examples in the GP were mostly around the data being necessary for fulfilling a contract (can't request deletion of your mortgage records) or meeting legal obligations (can't delete tax records). But there's also legitimate interest.
Legitimate interest is vague and open to interpretation, but I'd be really surprised if there were any decisions from a DPA suggesting that a VCS commit log would be problematic. The legitimate interest seems really strong in that case: being able to audit who actually made each change, e.g. for security reasons.
You can ask, but the right to have data erased is not an absolute right. In fact there's an enumerated list of the circumstances in which the data must be deleted but data controllers are otherwise under no specific obligation to delete data, and there are even a series of criteria which dis-apply that obligation.
Data controllers absolutely must delete data by default. The basic rule of GDPR is literally "privacy by default" (or "data minimization"), not "data hoarding by default". There are plenty of exemptions that grant companies the right (or rather require them) to delay the deletion by amounts of time as long as many years (e.g. for tax purposes), but they are only permitted to maintain only the absolute minimum required to fulfill these obligations and they must delete the data as soon as possible once these obligations have been fulfilled.
If you are obligated to keep a set of PII for 10 years, you must delete it in 10 years, unless you (still) have consent to keep it beyond that time limit.
It can't be "an absolute right... unless", it's either absolute or it's not.
And if you read Article 14 the first paragraph says that "The data subject shall have the right to obtain from the controller the erasure of personal data concerning him or her without undue delay and the controller shall have the obligation to erase personal data without undue delay where one of the following grounds applies" (emphasis mine) and then lists six grounds. Further to that, paragraph 3 dis-applies paragraph 1 for more reasons than "another law states you can keep it".
>The company doesn’t own your data, you do.
Data controllers do own the data (insofar as one can "own" data), but data subjects have rights over the processing of those data that limit what the controllers may do with them.
You can’t delete IP as this is not covered by GDPR, but you sure can ask them to delete your identification data from their records as GDPR also works for employees not just customers. It’s a problem with for example vcs.
Unless there’s another law in ruling, GDPR is the baseline. It’s for any identification of an individual, regardless of usage. Most “media apps” don’t have any other law that’s in effect, so GDPR is mandating what you need to do. (IANAL but worked on implementing GDPR with lawyers).