For one specific (but large) example, lots and lots of older people in these countries rely on economic growth to ensure that their savings/investment can pay for their retirement, since if economic growth stops they'll be far from wealthy, won't really be able to retire and this will create problems both for them and the general social structure.

As in, even "life as usual" is conditional on at least some economic growth continuing for decades; and even in wealthy countries most people does not consider themselves wealthy enough and will not be satisfied with the idea of things not getting better; they'll definitely throw out any politician who promises keeping status quo in favor of politicians who promise that economy will grow.