No it's not. Capitalism is a form of universal exchange and nothing more, it has been brought under control in some reasonable countries. American capitalism is a long term guaranteed failure though, but it's a boom and bust cycle and could go on into perpetuity. Doomers always underestimate human ingenuity. Money will move around to different “growth” industries until they collapse (like tech social media is right now, only so much you can grow).
You are confusing capitalism with market economies. The primary goal in capitalism is the accumulation of capital and that obviously requires endless economic and population growth. If there are less people, the need for additional capital decreases which means there is less capital to accumulate.
Capitalism is effectively an insane economic framework where the yield on capital is not allowed to become negative as that would go against the ultimately empty goal of capital accumulation.
If you consider capitalism to be a form of universal exchange then why exactly does the division of labor collapse the moment growth stops? Oh right, because capitalism and free(=freedom) markets are mutually exclusive. The interests of those who own and want to accumulate capital override those who want to exchange goods and participate in the division of labor, that is what a depression is.
Not the person you're replying to, but I think "current" and "system" in "current capitalistic system" are key here. They weren't railing against capitalism in general, but the current system, which is quite a different thing.
For my part, I'm not opposed to "capitalism" in general, but I have quite a few gripes with the current implementation of it.
There is no implentation of capitalism that will ever be unproblematic. No amount of bandaids is going to solve the fact that capital yields can be both positive and negative. When looked at it from this perspective, capitalism is a race to an end goal, not a goal in itself but once people are at the finish line, they don't want the race to finish.
