30 minutes out of town isn't nearby anymore. The highways are surprisingly efficient. And consider that it is more like a 1-1.5 hour drive for someone living on the opposing end of the city — possibly more if it is a large city. Advertising a job 1.5 hours away as if it is local doesn't tend to win you any admiration from job seekers. Maybe AI companies are prominent enough that they can piss off workers and still hire them in the end, but that doesn't fly for most businesses.

But, again, why take the risk when you can just as easily put the work right beside the workers?