These are excerpts from What is Economic Growth? by Holden Karnofsky

Key points

A bit more detail

Misconceptions and imperfections of the concept

Economic growth doesn't necessarily measure people getting richer (having more stuff per person). Economic growth can be caused just by population growth. There is a separate concept, "per-capita economic growth," referring to the amount of total stuff there is per person, which can be thought of as a measure of people getting richer or poorer.

Economic growth is subject to imperfect measurement. In particular, as estimated today, it only includes the value of transactions - things that people spend money on. So:

Conclusion

I don't think of economic growth as a perfect measure of what it's supposed to be measuring. But I think that major changes in it from year to year are usually meaningful.