Funfactlet: There's a steam locomotive in active duty shunting work trains around at the moment in western Germany. The Riedbahn between Frankfurt and Mannheim is currently being redone and they were short on Diesel engines, so one Verein for historic railroad equipment offered their steam engine and was accepted.
Another use for steam engines is for shunting duties in power plants - the engine has no boiler and just gets “charged” from the main plant steam generator.
A similar thing happened here in Australia (New South Wales) in the mid 80s. I was part of a rail preservation group and we were taking a stream locomotive with an empty train from West Ryde Station to Central, from were we were going to depart for an enthusiast's trip. One of the suburban trains was cancelled, so Jock, the station master, asked if we would like to run the regular suburban service, which we did. It was great fun pulling in and watching the passengers do a double take as their regular train turned out to be a steam train.
It's 19km from West Ryde to Central by rail. In the 80's there was still a modicum of infrastructure available for steam locomotives. I've a memory of their still being a water standpipe at Central. These days you would have to arrange with the local fire brigade to fill the tender.
https://www.swr.de/swraktuell/radio/riedbahn-sanierung-dampf... (German only)
Another use for steam engines is for shunting duties in power plants - the engine has no boiler and just gets “charged” from the main plant steam generator.