For the Berlin S-Bahn, there is a weird mix of automatic and manual announcement. Where the train is heading is announced automatically, whereas "Einsteigen bitte" (board please) and "Zurückbleiben bitte" (stay clear) is announced by the driver. I imagine a driver saying this every 2-3 minutes in an 8 hour shift.

But also, I disagree with the failure rate of 90+%, from my experience I'd say it works pretty well in 90+% of the time. The system can even announce the "umgekehrte Wagenreihung" ;)