Did I read this correctly and audio fingerprinting is mainly about identifiying the used browser version and OS or laptop, but it cant identify end-users in a stable way?
This is particularly a problem with big advertiser networks because they can track you across many sites you visit, even if you disable third-party cookies.
It has positive uses too, like preventing click fraud and concert ticket arbitrage.
I don't think that's what stockhorn said. stockhorn said it can only identify a what browser and OS and laptop model you're using. Someone else with the same browser, OS, and laptop model would have the same fingerprint. So audio fingerprinting couldn't precisely recognize you again when you come back again.
the collision rate of their ids is stated to be 0.05%
what they do is basically collect a lot of signals from the browser (audio processing stuff being only a part of it) and then compute an id on the server.
These practices and their repercussions aren't self contained.
There was previously a site which could indicate how globally unique your environment was (some combination of screen size, user-agent, fonts?, etc). Locking down to a specific hardware+browser configuration probably does a lot to remove anonymity.
Just being Linux + Firefox is terrible for blending into the herd. Let alone everything else that leaks (having a desktop + GPU + good monitor basically destroys all remaining hope).
The about page has some history https://coveryourtracks.eff.org/about