Growth isn't just about consumerism it's about human flourishing. We grow not just because we produce things we grow because we get better and better at using the resources around us which provide more flourishing for more and more humans. Without growth we can't do that as we won't have the surplus to invent and invest in new technologies.

Improve medicine, explore space, optimize production methods, invent new energy method etc. for more and more people. Those require growth.