The public Shopify app "Deletd", enables merchants to get an overview of the customers they have, that has not been active for a certain period of time. The length of the time period can be configured in the app.
Merchants might want to redact/anonymize customers that have been idle for a certain period of time, in order to fulfill privacy rules such as GDPR. The app provides links for the relevant idle customers, and the merchant can then use the Shopify built-in customer redact functionality to redact/anonymize customer data.
The merchant can also choose to tag idle customers, such that the merchant can get the customers on a list in Shopify at a later time, and treat them as they see fit.