I was part of the team that founded this, about 10 years ago if memory serves. I'm still loosely involved, though no longer at Google. Inconsolata was one of the 20 fonts for the original launch, and we're now in the process of launching it as a variable font, with both width and weight axes. I'm also getting funding from them for Rust-based font tools.
Feel free to AMA, though no guarantees I'll have good answers.
Was this created in order to track users across different sites or because google wanted to make the world a better place? :)
The latter.
Do you think it's still used for the latter rather than the former now?
I think Google might have better ways to track people. Fonts are also cached by CDNs and the local browser so I’m not sure if they provide good tracking data (they get loaded only for the first page visit for example and popular fonts like Open Sans are probably already in your cache when you open a page).
If you’re concerned about tracking as a website operator you can simply load the fonts from your own server, most of them can be found on Github and have liberal licenses (I think all fonts on fonts.google.com)
You can even install the fonts locally to your machine and your browser will favor the local copy. There are some tools like Skyfonts that let you install the top X from Google Fonts and it can be a fun way to speed up a lot of the web; with the tradeoff that not a lot of people have the top X installed for useful large versions of X and that becomes its own fingerprint for surveillance software (testing how long text takes to render in an off screen canvas, for instance).
It's been suggested that Browsers or Operating Systems choose a useful X value and install the top fonts everywhere like they used to install the classic "core web fonts".
Also there's a addon called "decentraleyes" that will cache fonts, amongst other things. It's one of 3 extensions I install in every browser I'm allowed to. The others are uBlock origin and https everywhere. All 3 have good privacy/security/performance benefits with effectively no breakage, in their default configurations.
https://git.synz.io/Synzvato/decentraleyes
Web developers who are concerned about privacy exposure from Google Fonts can use google-webfonts-helper to extract the font files and self-host them.