When I Google which one has more storage space, it says that minivans typically do. Maybe it’s spread out in different parts of the van and not just behind the third row, but my experience has been that you can fit more suitcases in the back of a van than you can in the back of an SUV.
If you clear out the people and just want to haul cargo, the minivan wins hands-down. Being able to fold down seat gives you a ton of space.
They definitely both have their advantages, but the minivan wins my vote unless you’re planning on towing a lot.