> I could sell an app in the EU that just pinged my server once a day. As long as I wasn't keeping a record of who pinged what when, there is no PII.

Data processing is not just about 'keeping a record'. Processing even for a millisecond is also processing.

> Otherwise everything is PII and you would need consent before every TCP handshake.

Consent is not the only ground for data processing. Normally, it would just be performance of a contract, as the user wants something from you.