is iphone 13 pro max still worth to buy in late 2025?

Also depends on where you are buying the phone and what condition it is in that may be unknown by you. Apple discontinued the phone 3 years ago, so you would really have to trust the seller and have an option to return it. The battery may need to be replaced or worse, it could be locked to the original owner and not even usable by you.

The All Too Common SAD Reality of Buying … - Apple Community

Depends on what you look for in a phone.

One thing to keep in mind is that the current iOS 26 supports iPhone 11 and newer, so if the pattern continues, the iPhone 13 may stop receiving major software updates after a couple more years.