Economic growth is a relatively modern phenomenon, and humanity did exist without it (or at least without very much of it) for a very long time.
Growing endlessly without limit is the model of cancer.
Economists have not thought through how we can continue growing year after year after year, using ever more resources, destroying more of our natural environment, and cramming more and more people in to already crowded places. Basically, most of them just trust that technology will sort it out somehow, and figure they'll be dead by the time resource constraints become a problem for them personally.
However, this is extremely wishful thinking. In western countries, our living standards - not just economically, but also socially and culturally - peaked some time ago and we are on the downward part of the ride now.
When I was an econ student, I sat in lectures where professors would talk about how we now understand how to achieve economic growth, how we can control business cycles, and this was the biggest lie - that future generations would continue growing and be better off than earlier generations. If somebody calling themselves an economist tells you something, it's most likely total bullshit, that's a good heuristic to go by.