You are right that it is work that needs to be done and should be paid for, but some local companies offer transport plus assembly in the price of IKEA transport only.
Also in Poland availability is different when I try to buy same thing online, check if it's present in local store, or order the same item to be picked up by myself from warehouse next to store.
It's even weirder! Sometimes I order things that are "present in my local store" with transportation, but the actual transportation is made from a central warehouse in different part of the country. So IKEA's "availability" is clearly a concept very different from what client might think.
> So, instead of you running around and picking stuff from the shelves, an employee has to do it.
Here warehouses are usually buildings next to the actual store. So in either case employee has to pick it up from warehouse, but with "pick up from warehouse yourself" option they don't need to transport it to the store next by. I still have to pay for that extra.
It's just weird.