Elon Musk — known for making bold, and by some measures outlandish statements — threw down the gauntlet to other automakers.

"The fundamental message that consumers should be taking today is that it's financially insane to buy anything other than a Tesla," the CEO of the electric auto maker said after Monday's robotaxi announcement. "It would be like owning a horse in three years. I mean, fine if you want to own a horse. But you should go into it with that expectation."

On stage at the Tesla Autonomy Investor Day in Palo Alto, California, Musk boasted about Tesla's self-driving technology, predicting his company will have more than 1 million robotaxis on the road next year.

"If you buy a car that does not have the hardware for full self-driving, it is like buying a horse," he reiterated. "And the only car that has the hardware for full self-driving is a Tesla."