These chaps (and chapesses) are ubiquitous around London - and can be annoying when going to work with a hangover, and/or in a crowded carriage.
One said recently on the Tannoy - 'a trolley service of drinks and light refurbishments will not be with you shortly'. Or on a longish route - 'this train has no toilets'.
However, they are very slow to make fun of the daily train delays which are now more commonplace than the days of British Rail - notwithstanding the high-tech rolling stock.