actually they are generally below replacement level, which (if not augmented by immigration) would itself lead to a collapse as people leave the workforce and there are fewer laborers to replace them. But people think we manage this labor shortage with technology, which leads us back to the requirements for more energy and capital development to maintain the same lifestyle.
> Also lifting everyone to the living standard of highly developed countries will require significant amounts of resources and significantly increase energy consumption, this however is also more like a one-time expense and I would therefore ignore it, too.
why do 'highly developed' countries need vastly greater resources to maintain this living standard if its a one-time expense? the greater standard of living your referring to requires continually expanding quantities of inputs in terms of energy and labor, aka 'economic growth'.
> How does dependence on technology demand growth?
its more related to the specific technologies we've chosen to build our society upon, but this technologies generally depend on these improvements to sustain themselves. For example, electric cars require batteries which require raw materials to be mined, recycling batteries requires chemical industry that is predicated on all sorts of inputs, themselves coming from nonrenewable sources.