The European Court of Human Rights has reminded this point (e.g. 29 Mar 2010, appl. no. 3394/03), and the Court of Justice of the European Union reaches a very similar conclusion (2 Mar 2021, C-746/18): prosecutors are part of the executive hierarchy and can’t be treated as the neutral, independent judicial check some procedures require.
For a local observer, this is made obvious by the fact that the procureur, in France, always follows current political vibes, usually in just a few months delay (extremely fast, when you consider how slowly justice works in the country).