I got 26 days at the local IT company where I started after university, and I now have 30 days at a big IT company (SAP). However, this is an IT worker's privilege. Among my friends in the manufacturing industry, the minimum 24 days seem to be common.
I'm pretty sure your friends in the manufacturing industry are bound by union contracts (Tarifverträge) which tend to define these things in ways that are meant to be difficult to adjust on a per-person (or per-company) basis to protect every worker equally.
I have friends working at agencies where unpaid overtime is the norm. I also have friends working in industrial jobs where they complain when they have to work 40 hours (rather than the normal 35) and every hour of overtime is merely compensated at 200%. Oh and he made a pretty decent wage straight out of school.
Talking about "privilege" in this context creates the false impression that all IT workers automatically have it better than traditional industrial workers in every aspect.
Edit: fixed no. of days