but I've noticed very few Folk/Trad artists seem to use it. (the only one I can think of that does is Johnny McEvoy)
Well either you need a venue with one installed and in tune or you need an electric keyboard and, in a session, a convenient power outlet. Without any effort I can think of four English musicians who I have seen playing piano or keyboard on stage (Reg Hall, John Adams, Gareth Kiddier and Ken Lees) although its not always their primary instrument. Among "traditional" (ie non revival) musicians Daisy Bulwer comes immediately to mind.