Well that, but more because the main pocket zippers like the one on #2 carry more stress when the bag is full. So they are more prone to break. Even if you don’t fill the bag to capacity the zippers move so they get lots of use. Zipping and unzipping. So why get a bag that has parts that will fail vs a bag that has no such parts. That is unless there is some component that the zipper style bag has that is important to you.

I prefer the first. The bag style usually has no zippers and while there are good zippers, no zippers are always better for a main compartment. It’s similar to my Deuter which I’ve had for 16 years.