Information, power, and insight asymmetry between an individual and a company. That’s why there are consumer protection laws in many countries; to even the scales, not to favor individuals. With no hand on the scales, asymmetry is the default.
I 100% agree companies shouldn't be outright allowed to scam people
but if you're not at least reading the wikipedia page on a car and its manufacturer company before buying it looking for common "issues", that's kinda your fault
a car is the largest purchase most people will make (after property)
people should do more due diligence on it than e.g. on a new phone purchase