You are imagining a single future invention in today's world instead of imagining it in the future world alongside all the other inventions that will also be there. That is what the person is referring to with no scarcity of resources. Imagine being able to 3-D print anything you want including food from abundant natural resources almost out of thin air.

As for as your other list of limited resources....we already have the technology here or almost here for solving this problems... the world can technically handle many many times the current population with some of these things in place.

Food - lab printed meat, protein from insects, vertical farming, etc.

Water - cheap desalination of ocean water

Shelter - 3-D printed houses, more high-rises, green communities, man made floating cities

Social - not sure what you mean here.

"And note streaming services, banking fees, etc automatically prove your scarcity claim false. Like look at how much of what you are paying for is artificial vs actual. As long as humans are in control, greed is king sadly."

Think about how decentralization is about to change the world as much as the internet has. Further, society and the economy will adapt if forced to.