I don't see why.I see a lot of fantasy RPGs driven by the imperatives of fantasy novel plots, which are almost always grandiose. I think those sorts of stories almost always need to railroad the players
I've run more than one FRPG involving a "grandiose" plot, without needing to railroad the players.
This is a description of the in-fiction situation. The "you", the "BBEG", the "world", the "choices", the "have to" and the "determine", are all elements of the fiction. It tells us nothing about who has authored that fiction; but railroading is all about authorship.after all, if you have to stop the BBEG to save the world, then that's going to determine almost every choice that you make.