Ideally mostly devoid of humans, but if there had to be large human societies I would change two things:
1. Eliminate scarcity from the get go. Make it so that in any given place there are enough (renewable) resources for every human to satisfy their needs. If this were the case it would eliminate the need for competition between factions, and therefore prevent wars and the tribalist state of mind that is still present in all of us, which would hopefully pretty much eliminate discrimination based on things like gender, race, sexuality etc.
2. Change humans in such a way that in a given situation they will always choose the least harmful possible action in regards to other people. Make it so that nobody would go out of their way to be cruel, but always go out of their way to be kind to others. This should eliminate a lot of interpersonal conflict, which leads to misery and infighting.
I guess there is an argument to be made that a lot of this cruelty and competition have led to great advances in technology and the arts, but I think humans would be industrious regardless, and this time in a much more sustainable way. And even if humans became "less" developed I think it would be completely worth it, if it meant an end to the sheer evil that people cause today.