How is logging all the things to a log aggregator helping privacy? In the projects where I used Splunk they were logging credit card details, transaction detail

How is logging all the things to a log aggregator helping privacy? In the projects where I used Splunk they were logging credit card details, transaction details, and PII all over the place, totally loosing privacy and security context data. Moreover, since Splunk is very expensive, only few gatekeepers got licenses, thereby not only concentrating power, but also questioning the usefulness of Splunk and Elastic Search (it being easy access and analytics on log data). I've come to see log analytics-heavy approaches and similar over-the-top event-driven astronaut architectures as an excuse for poor design.