There is artificial scarcity but there is also real scarcity. We do use more renewable resources per year than the earth renews and as such as we behave now we are overpopulated. Personally I like modern things and even though I reduce, reuse, recycle maximally I don't live like the amish or on a commune or such. If we did we would not be able to have our current population anyway as most of it is in cities. If we want to keep the cities then the population needs to be lower to not use more than the earth can handle. Even if people in cities lived super eco lives with what is achievable currently I doubt we could have over a billion. Keep in mind that even if we use less than the earth can renew in a year there are a variety of things we use that don't renew and that gets even more complicated.