How long do you think it'll take for all of humanity to unite and work together as a species?

I don't think that's likely, we are apes not angels.

Sometimes we have conflicts, some are probably resolvable, some represent fundamentally opposed interests.

We can try to make society different, so there are fewer situations that lead to irresolvable conflicts. That project will never end.

Whether this gives you hope or grief is largely up to you.