So, uh, let me try to convince you to play more. Minor spoilers ahead perhaps.
So, playing as 9S might seem at first to not be as good as 2B was. And you’re basically playing through the same events with a different character. And at first, it seems it’s not so different, so you might think it’s too much repetition.
But here’s the thing: that first impression is somewhat deceiving. You’re seeing the same events, but through the eyes of a different character. And this character has this ability that gives you new insights on what you’ve seen before. 9S is not 2B. He doesn’t perceive the world in the same way; he doesn’t see the world with the same eyes. That difference between the two characters is extremely important to build some of the basic elements that will be used in the rest of the game.
There are also new elements in the second playthrough - it’s not all repetition from a different point of view. And sometimes the different point of view changes completely a certain encounter. You’d be surprised to see how effective that can be, and I think you will by the time you make it to the “Carnival boss” with 9S.
I was a big fan of 2B when the first playthrough (ending A) ended. 9S didn’t seem to me to be as interesting, and he was certainly a lot less badass. I thought of him as JRPGboy sidekick, much like you. But by the time I got to ending B, I looked back and realized there was more to 9S than I gave him credit for. In many ways, the story is more about him than it is about 2B. It’s hard to think of that as a good idea at first. But then stuff happens and you see how much sense that makes.
In the end, though, the story is actually all about who’s playing the game. 2B, 9S, A2 are ways the game uses to make you peek deep into your own mind. It’s brilliant.
So yeah, you should play it. The repetition can be grating to many, but I’d go as far as to say that that’s part of the message behind the game. Life, as we know, is filled with busywork if you want to get to the good parts of it. NieR is ultimately about what life is, what it means (or doesn’t mean), about the nature of existence, about why and how we keep going in spite of suffering and pain and hopelessness and meaninglessness. To convey that, sometimes it must feel like a chore. But it makes up for that in spades.