Cars are a depreciating asset. Also quite often you lose more than you put in , in the case of writeoff/accident and there are insurance protections plans for debt etc.
Exactly why buying it cash can often be a wasted effort over buying it on a loan term.
Buying it cash implies that you have not overextended yourself, it is MUCH easier to purchase a car beyond your means if you use a loan.
It could still be a mistake, but it will be a cheaper mistake than a loan, guaranteed.
Sure there is an element of that, but then there is also the nature of over saving money to buy said car cash when the money should/could have gone elsewhere with longer term benefits.
For instance I could buy a car cash now by taking the money out of my home loan and then having not taking a finance agreement, but that means I don't pay my house off within 10 years etc.
There are also more critical conditions where a reliable transport offers you the opportunity to make money whereas waiting to generate the cash could see you not making money to achieve that.
Ultimately you can overextend yourself on a car purchase even if paying cash for it.
If I saved for 20 years to buy a Lamborghini Huracan cash at the expense of all else it would still be an over extension.
The trick really isn't HOW you pay for the car, but just HOW MUCH in relation to your earnings.