„For the benefit of the customer“ is too vague justification for it, you need a more specific reason.
You can keep data in your servers without consent if that data is there to serve the interests of user. In this case, the interest of the user is getting access to the games they purchased and paid for (!!!). This is called "legitimate interest".
A company can keep the address and phone of their customers if they're providing services. Package delivers don't even have to ask for consent to deliver a package to someone, for example. The law is not as stupid as Silicon Valley tries to paint it.
I'm pretty certain that Ubisoft is breaking GDPR and other similar laws in several places, but "keeping data to provide a service" is the one place they're not.
In real world nearly everything has an expiry date, beyond which product is no longer usable if you do not invest in maintenance. Who said that in digital world it should be different?
Reasonable expectation of account life time is the period when the user needs it, no more and no less, and it is not the same period as the life of the user.
As pointed out above, you are allowed to keep all data necessary to provide your customer what they purchased. Losing that data is not the customer's problem, but yours. If you cannot keep your customer data safe indefinitely, then maybe you should've settled on a business model that does not require keeping customer data indefinitely.
Passwords should be properly hashed. Heck, just delete the password and let the user ask for another if need be.
If there is ANY unnecessary data that was collected but that doesn’t need to be there, or that needs consent to be stored, just delete it. Easy peasy.
List of games owned? Email address? That doesn’t need consent, because it’s legitimate interest. It is 100% in the customer’s interest to have this information long term, and deleting it would cause actual loss to the customer that’s probably as bad as having PII leak.
What “cost of maintaining accounts”? Less than a kb of data per customer on average?
This whole thing is just to force customers to re-purchase games.
> In real world nearly everything has an expiry date, beyond which product is no longer usable
That’s clearly not true. There are several products that don’t have it.
But in the case of games it is worse, because the expiration date is 100% artificial: since the games need authorization servers to run.
If you can't keep first/last name, or birthday, just delete it.
However in pretty much every jurisdiction, keeping any kind of information FOR THE BENEFIT OF THE CUSTOMER is 100% allowed, encoded in the law, used as examples and is within the spirit of the law.
Any judge, lawyer or layman would laugh at the idea that GDPR can be used as an excuse to force users to re-buy products.