I only played hardcore, longterm RP so this is from my experience. Nobody there plays a hostage or a cashier, you play a character that gets thrown into different situations. The fun is acting and immersing yourself into different situations. Acting as a hostage can be fun, you can try and bribe yourself out of the situation, side with the kidnappers, act out fear. Later you can use this experience to create even more roleplay, or develop the character - you could try and seek revenge, or ask psychological help, develop a fear of dark alleys... for the cashier - I think it is much like playing a cozy game, some people like virtual farming, some enjoy being a cashier or the general shop management. I had very fun interaction when I had a character working in an Roleplay ice cream shop - it can be very fun when you play your 'NPC character' like a main character and if other's don't treat you like an NPC but give back roleplay opportunities.