Objective
Privacy is an important matter.
I would like to present several open source solutions that respect users privacy and will allow you to improve your business.
Disclamer
Analytics systems are listed in no particular order.
Often

From the homepage:
Offen is a fair and open alternative to common web analytics tools. Gain insights while your users have full access to their data. Lightweight, self hosted and free.
Key points
- Privacy friendly
- Transparent and fair
- lightweight
https://github.com/offen/offen
Matomo

From the homepage:
Google Analytics alternative that protects your data and your customers' privacy.
Key points
- Real time analysis
- Customizable
https://github.com/matomo-org/matomo
Fathom

From the homepage:
Fathom Analytics is a simpler and more privacy-focused alternative to Google Analytics.
Key points
- Simple website analysis
- Do not use cookies
https://github.com/usefathom/fathom
Links
https://github.com/offen/offen
https://github.com/usefathom/fathom
https://github.com/posthog/posthog
https://github.com/matomo-org/matomo
https://www.pexels.com/photo/police-blue-sky-security-surveillance-96612/