The current breeds of horses the Amish use are far stronger and healthier than they were even 100 years ago. For example, current draft horses are so strong they can outperform mules and oxen, and running horses are absurdly fast. I heard of a guy who regularly zips around at 20 MPH with a buggy or cart. That simply wasn’t possible in the 200s.

Of course the costs are higher too. Good horses in the above category can go for north of $100k.