Buying a new car after paying off the old one - is my friend right?

Hi all!

One of my friends buys a new (or lightly used) car on finance, pays it off, then starts all over again. Her reasoning is that, the money you spend on the original car, which after paying it off is now older, is just wasted money as you won’t get it back when you sell it.

I’m pretty sure it makes more sense frugally to just buy a used, in good condition car and keep it as long as possible, but I’m curious if what she says has any weight to it?

Thanks for any thoughts!