It's more than that. I'm a software dev, but I worked for a company that built machines for autonomous underwater titration (wtf chrome. How do you not know "titration"), and even in that nightmare of a task (moving parts, chemistry, batteries and underwater) it all ends up being way more consistent than software. When things fail, they tend to fail consistently and reliably, so building towards a reliable machine tends to be a simpler process. There is still complexity, (arctic and deep water applications), but often you can solve problems by just overbuilding the fuck out of it and not worrying.