Why aren't builders putting slat walls, e-track type tie downs in garage units?

[BravestDog]

Of all the garage units I've seen in pictures, they all seem to be lacking tie down devices like slat walls or e-track.

Like this unit here, an 05 Haulmark.

If I had a garage unit, it would be full of stuff like tools, carts, on and on. This stuff has to be tied to walls or else it's going to move all over when you start driving.

Anyone have a garage unit with tie downs?

[WERA]

Mine would too but honestly I'd rather do it myself for what I'm loading rather than have someone else guess at a generic setup.