As a non-technical founder my company pays Zapier thousands of dollars per year. We've automated a lot of tedious, manual tasks that you would typically assign a VA. I think we save some money, but even if it was break even, or more expensive than manual labor, the mental overhead of not managing another person, wondering whether the tedious work was done, and according to specification justifies the cost.
In my mind Zapier does things that a junior developer or maybe an office admnistrator would do, not an assistant. I feel like there is a small, but significant difference.