Source for thinking the degrowth crowd thinks this: Introduction to “The Future is Degrowth”. Does the degrowth crowd really think they can get rid of capitalism without any violence? This seems to have the opposite of a historical precedent, and is a deviation in Marxism, which they seem to heavily draw from. Anytime revolutionaries took the peaceful road they got outcompeted at best and massacred at worst.
Everytime i see the degrowth discussion out in the liberal internet wilds it tends to draw in thinly veiled ecofash or/and the magical hand of anarchism types.