Seems every camper we've purchased has less and less outside storage. But more inside storage. Our Outback 35 feet has only the one pass-through. We adjusted by getting rid of all the "stuff" we did not use when we switched to this camper! And it was massive!
The only challenge we had was where to carry the outside lawn chairs, and we found a comfortable spot inside the camper that works very well for that spot.
I did add a carrier to the bumper and carry a couple plastic boxes there to carry my sewer hoses. This way, they are outside the camper and not taking up bed space in the truck.
The bed space in the truck, and my construction style shell on the bed of the truck with full length shelves on both sides is were the bigger bulkier stuff is carried, like our blue sewer tote, my air compressor, tools, blocks, wood for under the tires, spare tire for the camper, ladder and water tank, and sometimes much more.
As the primary purpose for my truck is to tow the travel trailer, I usually keep everything in the truck bed or shell shelves all the time, unless I need the bed for something else. Then I'll remove everything from the bed, use the truck, and put it back.
Do I miss all those outside storage accesses like my last 2 previous campers had? No! Not at all. The more "space" you have, the more "junk" you haul around, stuff you don't need and never use. Limited storage space forces you to figure out just what you really do need, what you really do use, and forces you to eliminate everything else. It also teaches you to pack a bit smarter, and use the existing space wisely. In this case ... less really is better!
Edit:
I use the trailer bumper to carry poles and such: A long pole for a brush to brush off the leaves from the tops of the slide outs, a pair of fireplace tongs, hot dog sticks, my cane fishing pole I use for a flag pole (or in my case, a wind sock), a section of pipe. These are the long metal objects you really do NOT want in the pass through because they would probably punch holes in the floor or walls putting them in or out. Since I don't use this space for sewer hoses anyway, it's a great spot for those long metal objects. (Thus the reason for the bungie cords on the end of the sewer bumper in the photo above. Those metal objects can slide around popping the end caps off real easy! And then you loose them.