I care about avoiding war and avoiding exploitation.

Historically, the best way to avoid major wars, is to have a major power or an allies of power (possible in multipolar word), or strong enough attack power(nukes) to scare off the idea of war -- i.e a strong enough deterrent to make going war be a bad idea. No one wants to go to war if they know they will be destroyed. Like how a robber won't rob a house if they know a person with a gun will be waiting for them.

So if we want to avoid the loss of life on the scale of the world wars, then we need to avoid massive conflict between the major powers (who have the greatest destructive power by definition). Since they are major powers, with long alliances, a conflict with the U.S. and China would involve at least, U.S, China, Japan, South Korea, North Korea, Taiwan, the NATO countries of Europe, Canada. It's also very likely that it would involve Russia, India, Pakistan, Australia. Other countries that may be dragged in for strategic purposes would be essentially every country in Asia (including southeast Asia), North America, and the Middle East/any sources of oil.

The disruption to the balance of power, is extremely dangerous. That is the cause of war. It's creates such a powerful economic and political incentive to maintain dominance by obliterating the competition. Imagine your friendly giant corporation and their tendency to value money over everything, if they were allowed to kill their competition and killing them would lead to those sweet monopoly profits, do you think are moral enough to not just not just kill their competition instead of doing all that hard work of economic competition?

The fact that there's a strong chance of war is what concerns me so much about a rising China. Both the U.S. and China has the huge prize of being the dominant power if they destroy the other.

To maintain peace and avoid a huge loss of life, there has to be a big enough deterrence to make war not appealing. They each have to compete immensely in order to make the deterrence strong enough. This is why the U.S. and Soviet Union had an arms race. They also have to compete economically, so they can fund their defense.

Now, lets say war is avoided, and power is more evenly distributed. By definition, that means the U.S. has less influence than others do.
Then should another country do something that exploits the U.S., then by definition we have less power to stop that. This could be some trade deals that hurt the U.S. economy (i.e. jobs, and livelihoods of people) to the extreme of war against an alliance far stronger than us.

I agree that the U.S. has done some horrible things during it's hegemony, and I do not support them. But the brutal reality is that, others would do the same to us.

I think the best case scenario is that we avoid war and reach a new stable/peaceful balance of power, and the many now powerful countries provide healthy competition to the U.S. while still bringing wealth to themselves and their people. For the sake of my country and it's people, I hope the we the U.S. is still powerful enough to defend ourselves from foreign exploitation, competitive enough to prosper in that world, and free enough to enjoy the rights that many in countries like China do not.