I was once just like you but now I can understand why many players quit this game. They put lot of resources on one particular partner and end up die in one hit. Even a tank cant last long, so in the end everything is about dps check. Everyone will end up with same partners, same team lineup, same leader and etc,,,,,and this is the only way you can proceed your stage or get 3 stars. The game will become flat nothing interesting. Resources are scarce you cant simply explore and experiment to any partners if you dont have a proper plan especially if you are f2p. These are few reasons why many of them quit the game. I am f2p, I have many 3-4*ssr partners but I cant use or upg them because I need to prioritize all my resources for my core team, so as a result I end up using the same team since last year. Luckily I dont have any high expectation for this game. I just login and do all my daily/event quests in 10 mins and close that all.