"But how would we have <some technology> if not for capitalism?" is a misquestion, and you should not attempt to answer it. It is not relevant and will detract from the point.

We already have that technology. Abolishing capitalism does not require reinventing it. It can simply be used as-is, if it is needed. That problem is solved, and there is no moral imperative that says we should stop using it if we abolish capitalism.

What actually matters is whether a non-capitalist society could provide for people's needs going forward, and continue to improve itself over time, and *that* is the question to be answering. You don't measure that by considering work that has already been done.