I think the argument isn't "engineer" vs. "farmer", but rather engineer (or doctor, interpreter, commercial farmer/farm manager, industrial project manager, any other specialization that realistically requires years of training) vs. lower-skilled labor like farmhand, non-management/unspecialized construction worker, stuff that can be taught and learned relatively quickly.

I wouldn't call "low-skilled" workers _unproductive_ per se, and personally think they're incredibly valuable, but economically, the cost/difficulty of replacing a "low-skilled" worker is relatively low: it's a lot easier to find a replacement farmhand than it is a replacement farmer that manages the farm itself.

I went strawberry picking a month ago with my 4yo and she picked it up pretty quick. She'd have much more trouble joining me in my day-to-day dev job.

Picking strawberries is different than managing a farm. Imagine your 4 year old being a shot caller at the farm and how that might go. Would you have strawberries next season to even pick? Does your 4yo know how to sell thousands of pounds of strawberries?