Earlier quoted context omitted.
Why can't it be maintained forever? If a house can be valued at $4,000 one year, and $40,000 a few decades later, and $200,0000 a few decades later, what's the reason that "value" can't keep increasing eternally? There's obviously no real substance to "the value" of a thing, only people's interpretation and desire for it, and there's plenty of "value" where there is no physical substance at all, like exclusivity, or…
That's not growth capitalism. Growth capitalism requires constant growth in both supply and demand. Increasing supply requires increasing the usage of raw materials (not to mention the waste generated through their use). The reality is that we don't have an unlimited supply of any raw materials, so growth cannot be maintained indefinitely.
Recycling exists; Planet Earth has been doing it with organic matter for a couple of billion years without running out.