"Economic growth" as measured by numbers moving around is just a proxy for what we really care about, which is increased availability of goods and services. Goods and services necessarily entail resource expenditure. If you're just moving numbers without any actual physical effect, you don't really have an "economy" to speak of.
That is obviously true but not an argument for a limit. Availability of goods and services could grow logarithmically while prices could grow exponentially, you'd still see linear nominal economic growth.
I don't understand what you're saying. Logarithmic, exponential, it doesn't matter what shape the curve is or how fast you get there - all "growth" we care about is ultimately backed by expenditure of physical resources, which are clearly limited. If you redefine "the economy" in such a way that it's not limited, you also break its connection to the real world.
Honestly, all this talk about money is distracting from the core issue, which is that we are unsustainably increasing our consumption of limited resources.
"Economic growth" as measured by numbers moving around is just a proxy for what we really care about, which is increased availability of goods and services. Goods and services necessarily entail resource expenditure. If you're just moving numbers without any actual physical effect, you don't really have an "economy" to speak of.