Exponential growth can’t last forever, and I do worry about what will happen when the gravy train stops. Maybe we can figure out interstellar travel before it does so the limiting factor becomes “the galaxy” rather than “our planet”.
I think impending demographic collapse might give us a peek at that sooner than you'd think
Not everything is in the exponential growth model. Most small businesses in your town for example. Margins might afford an upper middle class lifestyle for the owner and that is a good enough business model for this company to last decades, even pass down through the family.