So I built Simple Analytics. To ensure that it's fast, secure, and stable, I built it entirely using languages that I'm very familiar with. The backend is plain Node.js without any framework, the database is PostgreSQL, and the frontend is written in plain JavaScript.
I learned a lot while coding, like sending requests as JSON requires an extra (pre-flight) request, so in my script I use the "text/plain" content type, which does not require an extra request. The script is publicly available (https://github.com/simpleanalytics/cdn.simpleanalytics.io/bl...). It works out of the box with modern frontend frameworks by overwriting the "history.pushState"-function.
I am transparent about what I collect (https://simpleanalytics.io/what-we-collect) so please let me know if you have any questions. My analytics tool is just the start for what I want to achieve in the non-tracking movement.
We can be more valuable without exploiting user data.
Regardless of your intentions, you are collecting enough data to track users.
> I am transparent about what I collect ([URL])
That page doesn't mention that you are also collecting (and make no claim about storing) the globally-visible IP address (and any other data in the IP and TCP headers). This can be uniquely identifying; even when it isn't unique you usually only need a few bits of additional entropy to reconstruct[1] a unique tracking ID.
In my case, you're collecting and storing more than enough additional entropy to make a decent fingerprint because [window.innerWidth, window.innerHeight] == [847, 836]. Even if I resized the window, you could follow those changes simply by watching analytics events from the same IP that are temporally nearby (you are collecting and storing timestamps).
[1] An older comment where I discussed how this could be done (and why GA's supposed "anonymization" feature (aip=1) is a blatant lie): https://news.ycombinator.com/item?id=17170468