Most of the Japanese big four bikes I've seen need some assembly by dealer once out of the crate.
The Port of Long Beach handles most motorcycle delivery. ALL their USA headquarters are not far from Long Beach.

The OEM's in California use a specialist assembly contractor to assemble bikes. I've been to various OEM warehouses in SoCal, witnessed assembly process. Imagine hundreds of bikes in crates awaiting assembly, then sent out to dealers all over the country. It all starts here.

Most times both wheels are off the bike, handle bars, seat,shield, sometimes plastic, all off. The workers were pretty much undocumented guys going VERY fast using really crappy tools ... NO torque wrench that I saw! (paid per bike)
(Suzuki warehouse in that case, been to Honda and Kawi warehouse too.)

We used to pick up our Press demo bikes there, that is why I was there, either for pick up or drop off.

The assembled bikes are then trailered to various dealers and unloaded.

BUT ... it's still dealers final responsibility to safety check the bike before delivery. Obviously, some don't do a great job, mistakes are made by low cost, zero responsibility assembly companies.

But sometimes seen crates delivered direct to dealer, especially KTM.
In this case, dealer does assembly or hires someone to do it.
Witnessed this too ... outside workers did the assembly at San Francisco KTM dealer. This all varies OEM to OEM but basically that's it. I have also seen whole trailer load full of KTM's show up, all assemble, ready to go. ALL small dirt bikes. BMW? Not sure.