A simple example of this is that water isn't used up, it gets dirty. It can be made clean again but that requires energy. This can be done by humans (water filtration) or by nature (evaporation and rain). We don't manage these cycles very well and they sometimes stretch out over too many of our lifetimes to manage (plastics, some nuclear waste) so it becomes easier to talk about resource 'use'.
The equation is pretty simple `humans × resources/human`. We can talk about reducing number of humans or reducing the resources needed per human. If we manage the cycles well, humans could inject more resources into the system instead of taking away from it. Of course this would still be limited by available energy. In that case, increasing the number of humans within energy capacity could benefit ecosystems.
We already have a lot of available energy but there is orders of magnitude more available as our technology improves — fusion, thorium fission, solar, wind, tides.
In the US we build shelters either out of carbon-intensive materials or use significant carbon fuels for upkeep... or both, usually.
It's not that the technology isn't there, we just choose not to. Hell, some 30% of people love that reality star turned president. Sadly we're getting what we deserve.
Changing our farming methods to increase humus and topsoil quality should bring back vitamins to our food. Not only this but it should also capture a great amount of CO₂. I'm not sure how reliable my memory or the original calculation are but I remember reading in "The Scientist as Rebel" that if we increase our topsoil by 2 inches on currently farmed land, that should capture most of the carbon we've emitted during industrialisation.
Of course, as you mention, if we keep mindlessly following the status quo, we'll keep getting what we deserve.