Why do they also have a system?

Reborn in the body of a young Uchiha, Gin gains his system just like any good isekai protagonist, but after some time this same system simply disappears. He thought that with the help of this system he could someday defeat Madara or even Kaguya, but he didn't expect that the system would just help improve his physical fitness and then disappear. While Gin was still panicking, he didn't expect that every heroine or supporting character would also gain a system, and then come one after another after him. "My goal is to become Uchiha Gin's wife!" Kushina screamed loudly, full of dissatisfaction in front of the entire room. “Uchiha Gin, be my apprentice, follow me and become my husband!” The corner of Tsunade's mouth twitched, wishing she could punch the system in her mind! “Gin, I haven't communicated with you in a long time, today…” Mikoto smiled, wanting to dismember the system. "What the hell is going on with these women!" Gin shouted in bewilderment. (This fanfic was made based on another fanfic that I read a few years ago, and it was abandoned without having an ending, so I decided to take advantage of it, make a similar fic and give it the deserved ending.) (Give me a hand on Patreon if you can, this fic like my others are updated three times a week with 27 chapters each on Patreon, so if you want, give me a little help there and enjoy the advanced chapters.) My patreon is: patreon.com/LordBlake167