No online games lasts forever, and idol rhythm or mobile games hype will die eventually imo... Which is one of the reasons Aqours are here in the first place, as other mentioned. As long as they keep updating the game with new content and gain profit from it, the game won't shut down for probably as long, but no one will know when. My only hope is that when SIF's (or just any idol games I'm playing in general tbh..) time has come, it's probably already years later and I'm already done with a lot of my goals in the game and maybe...well, to be frank, it's much sadder when a game shuts down while I'm still hyped for it and still playing it (like what happened to Idol Connect for me, unfortunately) so it's better if it happens when my hype for SIF died already, I don't even know how many years I will continue playing the game myself due to more IRL reasons coming and more fandoms and interests taking over. Just my personal opinion, though. For now, I don't really wnat to think more about it and I'll appreciate and cherish every moment I had with this game.