It all sounds great until you encounter an actual robo-taxi in the wild. Which is rare: Six years after companies started offering rides in what they’ve called autonomous cars and almost 20 years after the first self-driving demos, there are vanishingly few such vehicles on the road. And they tend to be confined to a handful of places in the Sun Belt, because they still can’t handle weather patterns trickier than Partly Cloudy. State-of-the-art robot cars also struggle with construction, animals, traffic cones, crossing guards, and what the industry calls “unprotected left turns,” which most of us would call “left turns.”

The industry says its Derek Zoolander problem applies only to lefts that require navigating oncoming traffic. (Great.) It’s devoted enormous resources to figuring out left turns, but the work continues. Earlier this year, Cruise LLC—majority-owned by General Motors Co.—recalled all of its self-driving vehicles after one car’s inability to turn left contributed to a crash in San Francisco that injured two people. Aaron McLear, a Cruise spokesman, says the recall “does not impact or change our current on-road operations.” Cruise is planning to expand to Austin and Phoenix this year. “We’ve moved the timeline to the left for what might be the first time in AV history,” McLear says. …

This, it seems, is the best the field can do after investors have bet something like $100 billion, according to a McKinsey & Co. report. While the industry’s biggest names continue to project optimism, the emerging consensus is that the world of robo-taxis isn’t just around the next unprotected left—that we might have to wait decades longer, or an eternity.

“It’s a scam,” says George Hotz, whose company Comma.ai Inc. makes a driver-assistance system similar to Tesla Inc.’s Autopilot. “These companies have squandered tens of billions of dollars.”