NGL, when i saw the name of the thread i actually looked up which solo duty it was to potentially offer assistance. A few i remember by name, most i do not. Clearly this assistance is not needed, congrats on clearing the Estinien fight. So to answer your question, they see these "play as someone else" duties as a storytelling tool. Why TELL you that Estinien fought his way out of the castle and ran into a strange prototype along the way when you can PLAY the sequence. As such, some people love them and of course some people hate them. You will continue to run into them from time to time. It is very rare to get more then one of them between full group dungeons(and indeed, you did a dungeon already in this patchs content - Grand Cosmos and the Estinien fight are the same patch). And indeed, group dungeons, trials, raids, and solo duties where you play as yourself FAR outnumber these "guest role duties". Off the top of my head, i cant think of the next one youll come across or how far away that is. But if you need help with it when you do, we're still happy to provide.