> In finance or medicine, it's often illegal[0] to delete customer information before the end of an expiration period (minimum several years).

There are also laws that require you to delete customer information. For instance patient data in situations where consent is withdrawn. So either way you can’t rely on “it’s often”. And on the flip side of things the legal requirements you are referring to are typically the audit requirements, which are still better served using audit tables, since it’s not enough to have a “current data” and “data that is currently not active”, since you need logs of who changed the data when, and you can easily run into situations where something is soft deleted, then restored, then soft deleted again.