When I was a non-programmer trying to build a business that needed software, the last thing I wanted was to rely on something I couldn’t maintain myself. For example, I could wire up DNS by hand, but the last thing I’d want is to have to learn Terraform just so I could update my email MX records. Using Herkou because I didn’t want to manage a server was another example. Using something like Zapier to add a row to a spreadsheet or send an email is also amazing.
Re-reading, you're definitely right. Where I got confused was the "Terraform/Heroku is bad because it adds another layer" but then not understanding why Zapier is better?
Creating a Zap that is hosted by Zapier isn’t just easier than hiring a programmer, it’s also operationally easier. Zapier’s team handled all the devops headaches. Yes, it could be more expensive than a budget developer, but I’d have to maintain an ongoing relationship to handle problems in a way I would not with Zapier. The headache isn’t worth it until you really need something so custom that Zapier couldn’t easily do it anyway. Hire a developer when you need one, and not before.
Regarding Terraform, installing it, learning HCL, understanding the state management, maintaining a place to run it, and learning how not to screw it up were all headaches I did not want.