Yes, if our population soared to 20 billion then we may not have enough trees. Or if people start destroying their chairs after only a year.
But how about we limit our discussion to reasonable limits and not stretch into the improbable in an attempt to win a point?
I'm not stretching into the improbable because in the real world people need an awful lot more than just chairs - the metaphor may seem stretched to you, but only because you aren't thinking about the countless other things people need (or think they do).
The bottom line remains very simple - growth has a limit, beyond which you can not sustainably expand (and another limit beyond that where you cannot expand unsustainably either).
Worse, some resources are renewed over geological timescales (or possibly not at all) and there is no precisely sustainable rate to draw them down at (modern civilisation is absolutely harming future people in this way by squandering so many finite resources).
Any sustained growth at all and you will ultimately run out of chairs. It is that simple. The terms sustainable and growth are contradictory, growth cannot be sustainable - it must end, preferably at a steady equilibrium - or in the modern world most likely with an almighty crash because we're eroding our limits and using even renewable resources in a non renewable fashion (and yes, even wind and solar power are subject to limits!).
Given we are already beyond sustainable parameters on even renewable resources in many cases, degrowth is the only way to put the system back into a safe state in a controlled fashion with a minimum of human suffering. I am under no illusions myself about this happening. We will fight instead, competing for a dwindling resource pool to the end.
I realise this notion may not sit well with affluent populations composed largely of members behaving in this dreadful manner, but it's OK - the crash will fix it in the end either way. The laws of physics cannot be bent by hopium and dogma. We act as though we have all the time we want to solve these problems, presumably because we created them and somehow think we therefore control them.