In Germany you can also go to court and certain phrasing needs to be dropped according to the courts.
The valuable piece of information in an Arbeitszeugnis that it will tell you is, if the person "verlässt die Firma auf eigenen Wunsch", i.e. if the person resigned from their position, or whether they were let go.
Technically even that would be invalid in Austria, if you actually go to the AK (Arbeiterkammer)[1]. So this in turn results in everything being in the superlative. Along with that, the AK is something you just do NOT want to get into trouble with.
[1] https://www.arbeiterkammer.at/dienstzeugnis