Investor Ross Gerber says Tesla's Optimus faces a long road, with humanoid robots difficult to build and unlikely to generate revenue soon.

Elon Musk spelled out the difficulty of making Optimus dexterous, reliable, durable, and safe, and why it will be tough to ramp up production.

Tesla is preparing to build Optimus in Fremont. Here's what we know about the humanoid robot's price, capabilities, and biggest hurdles.