To elaborate, economic growth requires a baseline. The baseline from which to measure is a function of available person's to labor, and capital at hand. To grow there must be gain in the output of this capital to labor ratio.
Increases from tweaking the capital side of the ratio requires investment. Investment requires savings. Savings are antithetical to consumption, therefore shunned in consumer demand driven systems. So go ahead and rule jiggering the capital portion of the equation in the age of modern monetary theory.
Well I'm glad you inquired about innovation.... Innovation to enhance the quality of capital or stock of knowledge among labor also requires investment, and thereagain savings. So rule out technological change as making meaningful contribution to economic growth.
What does this leave? We are left the labor (population) portion of the ratio in hopes of achieving growth... (Again because tptb cite growth as reason for incumbency). Can the population side be influenced without resort to savings? Yes it can by among other things ideologies, persuasion, starvation, epidemics, war, etc....
And so there you have it my attempt to unpack the slight of hand, population is the side of the equation tptb can manipulate all day long it seems.