Last spring, Bhairavi Desai, a middle-aged woman without a driver’s license and thus an unlikely leader for thousands of mostly male drivers in the world’s largest market for hired vehicles, delivered emotional testimony in front of New York City’s Taxi & Limousine Commission about the mounting existential difficulties in her field.

The executive director of the New York Taxi Workers Alliance, Ms. Desai had been a labor activist for 21 years but she had never seen anything like the despair she was witnessing now — the bankruptcies, foreclosures and eviction notices plaguing drivers who were calling her with questions about how to navigate homelessness and paralyzing depression.

“Half my heart is just crushed,’’ she said, “and the other half is on fire.”

The economic hardship that Uber and its competitors had inflicted on conventional drivers in New York and London and other cities had become overwhelming. For decades there had been no more than 12,000 to 13,000 taxis in New York but now there were myriad new ways to avoid public transportation, in some cases with ride-hailing services like Via that charged little more than $5 to travel in Manhattan. In 2013, there were 47,000 for-hire vehicles in the city. Now there were more than 100,000, approximately two-thirds of them affiliated with Uber.