I wouldn't say capitalism is based on the notion of infinite growth, but it is an inevitability of there being no limits on capital accumulation. The notion that humans have endless desire for more, always needing a stronger hit to maintain personal satisfaction, is more psychological than something inherent to private ownership itself. Capitalism feeds the natural animal reward system to disastrous effect, but it isn't required for capitalism to work. In fact, insatiable desires are the reason capitalism doesn't work, because if people could be satisfied with a reasonable amount of resources, never trying to acquire more than they need, capitalism would be a fairly decent system.