If you have humans in a perpetual state of bliss, they loose the drive to do anything. Because if your current state is perfect happiness, why would you do anything?

So if you put them into a genetically engineered state of perpetual perfect bliss, they might as well not exist. Or be replaced by statues.

If you still want motivations for people to do anything there needs to be different states of happiness, or in other words a less desireable state in that they are in and a more desireable state that their actions might move them to (or the opposite, a less desireable state that they would move to by inaction).

Once we have these basics down, there is potential for conflict as soon as one's goals conflict with someone else's goals.

And these conflicts don't have to be about materialistic goals. They could be e.g. about idealistic goals.

You can see that in our current world as well. If people are starving they might fight for food. But if people are well fed and things are going ok, you get an Arab Spring. Now people are all of a sudden not fighting for survival, but for idealistic goals like freedom.

Or take a look at Central Europe. Over here things are going pretty well (at least before Corona). Almost everyone has enough to eat and even homeless people are rather rare. But still you get Neonazis and Antifa who fight eachother, not because they are starving, but because they project their unhappiness onto some other group of people.

So even in a world of utter abundance there is a lot of potential for conflict.