Is it safe to assume that websites/apps keep the history of all data ever entered into our profiles like email addresses, phone numbers, names, payment methods etc? There´s no point in changing the data and pretend we´re pseudonymous henceforth is it? Old data will always be tied to the account?
If so, changing the data before closing (or abandoning) the account in favor of new ones with clean slate is still best practice, right?
That may vary based on the business, but my guess is any large business absolutely keeps a permanent log of who owns and pays for a given account. The only benefit to pseudonimizing that information after the fact would be privacy benefits on the public-facing portions, such as your name on Facebook or Amazon reviews.
Best to delete the account but still assume that the information remains available as a shadow copy on the server side