Maintenance and repairs are much more mileage-based than time-based though. If I drive 2X the number of miles in a year because I'm driving for Uber/Lyft, my maintenance/repairs on average are going to be about 2X what they would have been otherwise.

It's hard to tease apart fixed and variable costs in car ownership and it varies based on factors like climate. But, overall, car costs are significantly more about the number of miles than the number of years given relatively typical driving patterns.