I my view, in this age of Health and Safety, request stops are create a higher risk than is necessary to a passenger wishing to join a train, particularly on a line where there is a mixture of stopping services and expresses that pass the request-stop platform.
At major staffed stations, if you cross the yellow line or tactile paving, you can expect to be shouted at by the platform staff. However, if you want to join a train at a request stop you are instructed to hold your arm out but remain in a safe place on as you do so. However, most passengers don't and stand a little to close than perhaps they should, if it was a major station the platform staff would be screaming at them!
This is all very well, but what if the approaching train is not the service you think it is, for example a late running fast express or a freight train. It's not always obvious, especially to most non-railway people whether the approaching train is their service, (especially at night), not to mention that the platform information displays are not always the most reliable of info systems, (when they work that is......).
The timetables all take account of request stops anyway and drivers approach them expecting to stop, so surely for the sake of safety and risk reduction request stops are a unnecessary historical anachronism in this day and age?