Tack firms and Sub-Contracting

Just want to begin this with a caveat that this isn't me ranting about foreigners in Liverpool or some reform tackle - it's coming from a genuine place of concern. 

I'm noticing more and more that every time I get into a taxi the driver can't speak any English at all, doesn't know many of the main roads within the city and are often driving a brand new car. This in turn makes me wonder how - without speaking any English - they've navigated the process to get a license, finance/buy a car etc.

I've long had a suspicion that people are exploiting these drivers, providing them a vehicle and paying them a small wage to operate the taxi on their behalf - on their license/permit.

In short I genuinely believe there's something akin to modern slavery going on - not by the taxi firms themselves - but by individuals registered with the firm as an employee.

Wondering if anyone has had a similar thought/knows this is a thing or whether I'm being an absolute tin foil hat.