My old Electrician Boss was like this. Shit randomly thrown anywhere in the truck cab and bed. I started organizing it with recycle totes. But a few jobs later it would be a disaster again. He didn't quite realize that saving 30 seconds tossing stuff anywhere when packing up, turned to 5 minutes searching for that item when on site.
There's tie-down loops on the side of the bed. I just have big bolts that go thru the loop and screw directly into the 2x4 of the storage shelve. It's attached in three points.
Nice. I'm sure it makes a big difference, keeping stuff out of the way.
Though I don't know that I'd trust those nails/screws to handle the dynamic loads of a vehicle. I'd want the vertical supports directly under loads, so the fasteners just keep things together.
A friend made a ply tray on small ball rollers for stuff up in the front. He puts toolboxes on it, the tray has a lip so they stay in place, and he uses a piece of cord to pull it out. Ingenious. But I really like those drawers of yours.
I've been considering a similar setup for overlanding. I just need to set it up in a way that the whole kit is removable, but I can still strap it down to the tie down points in my 4Runner.
This setup is designed in a way that it can be quickly removed as well. The thing with the drawers is just held down with a single ratchet strap. Once you remove that it slides right out. The shelve on the other hand is held down with 3 bolts attached to the tie down points on the side of the bed. This can all be taken out in around 10 minutes.