With the rise of laser, microwave, and energy weapons, we are returning to a time of armor.
Copper or silver chainmail disrupts emfs.
Kevlar or silk underneath will slow projectiles.
Metal shells with ornamentation - angular lines, mirrored surfaces, rounded corners, will prevent detection and blunt force.
With all new cars being vulnerable to hacking and control, horses will become a viable option for mobility again.
So let them move towards "the future". We will become beautifully armored knights again. With purpose.
Horses can understand English commands, they can self navigate on an open road, self feed and easy to maintain
Not to mention you can produce another horse by breeding, can you produce another car?