A lot of drivers are acting irrationally (in the economic sense). The number of miles you put on driving for a car service will almost certainly be consequential to your car’s service life, if you are making any money at it. But, new drivers see cash in their bank account every week, and it’s hard to link that to having to splash out $25k for a new car down the road. I expect a lot of these drivers will bow out when their current cars become too old or damaged to keep driving for hire, since they won’t actually have saved enough money for a replacement.
Having people who don’t understand how to calculate their costs in the market drives down wages for everyone.