New cars need regular maintenance too.

The upside is you "know the history" and can reasonably assume that if you do the maintenance the car will last a reasonable time. And if not the warranty and laws (lemon law) gives you some way out.

Buying used you do not have the knowledge of maintenance, nor the lemon law protections, nor the warranty protections (third party warranties are pretty much scam). So you're relying on the gamble that the car you are buying will last, or you can make it last.

People with knowledge of vehicles and ability to repair have a leg up in that gamble, but it's still a gamble.