This is true, however since laptops with DVD drives are becoming harder to find unless you go to larger gaming laptops, the solution could be to purchase a USB DVD drive to plug into a laptop. But DVD drives consume a lot of power relative to the rest of a modern laptop, so battery life will probably be terrible. But it certainly is an option, particularly if you have a power source available. USB DVD drives start around $20 on Amazon.Another option is a laptop with a DVD drive.
Have had three of them, they all died an early death. It doesn't take much of a laptop to watch DVDs. I have an old Pentium III running Linux one of the grandsons uses to play them on. Battery life isn't great anymore, but if you're camping with hookups it doesn't matter much.USB DVD drives