Conversely the people who argue against growth never have any answers they want to elaborate on. They have "well we can't have endless growth" and that's where the conversation stops.

They never want to examine the consequences of that thought (no growth means we're into a zero-sum game) or whether they think we're even plausibly close to the limit (instead they want to have a proxy argument about environmental damage or global warming, and are very uninterested in any specific solutions to their go to examples - i.e. "we can't possibly stop emitting CO2 from power generation, we must simply use less power!").