Growth means prosperity and the more ideal money will allow for more sustainable growth.
It appears you have not discovered the inevitable endgame of our civilization unless humans turn the earth from a closed to open ecosystem by leaving the planet:
https://en.wikipedia.org/wiki/Steady-state_economyBut things like the speed of light means it will likely always be a closed ecosystem. Instead of "more growth" it's also likely the human population craters down to 500 million since the earth only has that much sustainable arable crop land to support humans with. That and the whole peak oil and natural gas thing.
Growth is overThis is not how things work in general
Some two-three thousand years ago people most likely had been thinking along the same lines, though the numbers were a few orders less of course (say, that the Nile river could only feed a few million people). What you call as the end of growth is only the end of growth in the current technological paradigm. But we have already been through a few of such, and there is absolutely no reason to think that there won't be a few next technological shifts in the future. Basically, what you refer to as growth being over in fact refers only to the limits of our current knowledge and understanding. A simple but explicative example (your example really), a few hundred years ago people thought there was no speed limit, then they started to claim that the speed of light is such a limit. Now this position is no longer considered valid and people again think there is no such limit