Here I agree totally. That is indeed a highly toxic problem of current society, because people are just accepted if they do the stuff like it is done since a long time. I think there is a movement into the right direction, but still it is on the frindges and slow as the system is, it will take a lot of time to get enough positive feedback.
But on the other side I am not too sure if it is right to say we need more "I" instead of "we". For Japan I definitely agree, at least in parts but looking for example to Germany, there is in my eyes too much "I" and too less "we". A lot of people just think about themself instead of how to live with other people together. But that's just my opinion.
I think that anyone who truly wants what is best for others will always come to the conclusion that “I”—the individual—is the foundation for anything legitimate. Indeed, only individuals think, and only individuals act. A “collective” can do no such thing. I’d say what you describe as thinking only of themselves is actually an ignorance and refusal to truly consider their individual life. Once we see we are the primary movers in our own lives, we realize that helping others ultimately makes our lives better as well.
I hear you, though, and don’t disagree, regarding that tendency in the US.