I indeed do not know Plausible and any of their motivations.

Google Analytics also does not provide PII to their end users per se. But I have seen many tools and solutions do just about anything to circumvent that. Merging analytics with transactional data and site logs. Adding company info to visitor data. There is an entire industry there.

So, an imaginable use case would be to self host it. Intercept to circumvent the limitation.

The reason why I am so cynical is not because of the motivations of Google Analytics or Plausible. It is what motivates the end users, the companies who are using these statistics.