The only way to try and get everyone to follow communism is through force, which requires a state, that is true. This is why I prefer anarcho-communism, where there is no state enforcing it.
It is also true under anarchism people have the option to not cooperate peacefully. As you said, humans are still humans at the end of the day and some will take advantage of others or hoard resources.
But I don’t think that is reason enough to not at least try to get there. Because under capitalism those same issues still exist, only people are expected to be okay with losing their autonomy and giving up their resources for the sake of a wealthy ruling class.
I certainly agree that reasonably there should be no need to go against humanity when resources are shared collectively and needs are met. However, humans don’t always act in a reasonable way, not to mention sociopaths and psychopaths that may place short term gain ahead of long term stability.