Why do people say you shouldn’t buy a car in cash?

A friend saw me at a car dealership last week and brought it up today. We ended up talking about it until he said it’s “best” not to buy a car in cash since it’s a depreciating asset. To be clear, I did not disclose that I will pay it in full, it was just his assumption.

I’m fully aware that a car depreciates that’s actually why I prefer paying in full, to avoid bank loan interest. Am I wrong with that approach?

Another question: the funds will be coming from outside the Philippines into my dollar account. Should I pay in USD directly, or convert it to PHP first?