He didn't sit around waiting for a job. He'd go about his business and when his phone pinged he'd decide in the moment if he wanted to do the job.
Sometimes we'd be watching TV and his phone would ping and he'd get up to leave. Sometimes he wasn't interested and he'd let someone else get it.
The issue with Uber, Lyft, etc isn't that they treat their drivers as contractors. People who have they option of when, where, and whether to work and are paid per task aren't employees. The problem is the pay is terrible for what they're doing.