That's a bet that many of us are not willing to take. Sure, you can imagine that a future technology we haven't thought of yet will save growth, but I think it's very important to think about scenarios when that won't happen. Are we really wanting to bet humanity's future on just "technology"?
If you read Collapse: How Societies Choose to Fail or Succeed[1], you'll realize that socities that did collapse were over confident. Let's no repeat that mistake.
[1] https://en.wikipedia.org/wiki/Collapse%3A_How_Societies_Choo...