(Btw, steam engines didn’t replace horses pretty much at all. The internal combustion engine did.)
As an aside, horses are still economically useful (although in extremely small numbers) other than for recreational or tourism purposes: they’re still used for logging, for instance, because they can handle rougher terrain than vehicles designed for similar use, and don’t get stuck if they run out of fuel.
Contains realistic numbers and actual observation, not just hand waving. Check.
Punctures the hype bubble driving a trillion dollars of irrational CapEx. Oh dear. Alarms sounding in the distance.
I expect everything about this to be downvoted into oblivion. As the emperor has so wisely commanded, the spice must flow.