The self-driving car hype cycle is in another depressing slump. Last week, Tesla boss Elon Musk admitted that full self-driving software is not yet ready to be used without someone behind the wheel. Mobileye, Intel’s autonomous driving unit, lowered its expected valuation from $50 billion to $16 billion. Several media outlets published stories mocking the sector for its failures after billions of investments.

The amazing thing is that all this happened at the moment when robot taxis arrived on the streets of San Francisco. For $10 or so, you can catch a driverless car from the famous Painted Ladies in Alamo Square to the bars on Nob Hill, watching from the back seat as the steering wheel turns on its own to navigate traffic.

The test scheme was launched by Cruise, a self-driving car company majority owned by General Motors. Like Uber, it has an app where you can call a car to pick you up. The prices are also the same, although the journeys are supposed to be cheaper once it takes off.

It’s confusing to see a driverless car stop next to you and listen to a robotic voice tell you to fasten your seat belt and enjoy the ride. But every trip I’ve had has been perfectly smooth. Cars are careful drivers when they notice obstacles, which is very reassuring for nervous passengers. It could also account for reports of cars stuck on the road blocking traffic. After an accident with a speeding car, Cruise recalled its robot taxi and updated its software. The plan is now to expand the scheme to Austin and Phoenix.

When you use a self-driving car to get from one part of the city to another, it feels like you’re living in the future. Sometimes it can seem like all the tech money is pouring into digital advertising, cryptocurrencies, and consumer apps. After living in San Francisco long enough, your phone will be filled with apps for every convenience imaginable. But autonomous vehicles, an ambitious, complex and potentially life-changing sector, offer a more tangible example of technological progress.

Of course, it was an outrageously expensive event. According to McKinsey estimates, since 2010, the total investment volume has been more than 100 billion dollars. According to CB Insights, self-driving car companies topped $12 billion in funding last year alone.

Development was much slower than expected. The dream of driverless cars has been around almost as long as the car itself. The modern era can be attributed to Google’s self-driving project, now Waymo, which began in 2009. By the time I arrived in San Francisco in 2018, it seemed like driverless cars would surely be on every road in a few months. Uber has claimed it will soon do away with human drivers, while Waymo and Lyft have launched robotaxi schemes in Phoenix and Las Vegas. Everyone from SoftBank to Apple has invested in self-driving cars.

Since then, however, the sector’s fortunes have declined. That same year, a self-driving Uber car killed a woman crossing the road in Arizona. The tests were stopped, and optimism collapsed. Two years later, Uber sold its self-driving car unit to local startup Aurora.

The task remains significant. Driverless cars must not only manage the mechanics of the vehicle, they must understand the world around them and make quick decisions when circumstances change. There is also still no consensus on how they should work. Cruise maps the roads it drives by mixing road data collected by cameras and lidar laser sensors. Tesla called the leader a “crutch.”

If the infrastructure for driverless cars could be built from scratch, things would be easier. The roads are busy and dirty. They are full of different users making irrational decisions. Cars must not only see an obstacle ahead, but also know if it is going to move, and if so, in what direction.

Cruz’s robotaxi test is quite conservative. Cars can only drive between 10:00 PM and 5:30 AM. If I want to show visitors the wonders of autonomous vehicles, I need to wait for night and make sure I’m in the right part of town.

Still, the money keeps coming. Either self-driving cars are an example of misjudgment of unavoidable costs, or their slow launch is not seen as a barrier to eventual adoption. Uber has signed a deal with Motional, a startup partnering with Lyft to offer autonomous rides in Vegas. Volkswagen’s automotive software subsidiary Cariad is investing $2 billion in a partnership with Chinese chipmaker Horizon Robotics. Waymo plans to expand its robotaxi service in Los Angeles, and Cruise hopes to get regulatory approval for a robotaxi without pedals or a steering wheel.

It was a slow and expensive way. It could be years before self-driving cars become widespread. But for many of the world’s biggest companies, self-driving cars are still inevitable.

elaine.moore@ft.com