Rowreach
Adjusting my sails
Seatbelts are a fairly recent idea too ...I have no idea why one should wear high viz when riding in Hyde Park. I didnt.
High viz for riders is a fairly recent idea. I have high viz for winter but the rides in Hyde Park are a simple circular route. A horse and rider are hardly likely to disappear.
As for RIs using phones on horseback, it is often to provide clients with souvenir pics. I dont do it myself but that is personal choice.
They absolutely should not be using mobile phones for any reason whilst riding on the highway.