For Ikea, simply open website, find product, look at aisle number, walk to aisle in warehouse. Done. They also have a consistent selection of products available. If you've done the tour in the past year, chances are you already know the product you're looking for and chances are they'll have it in stock.

Ikea actually minimizes it if you know what you're looking for. Try doing that at Costco where they re-arrange the store just to make you have to look at things you didn't intend on buying. This practice has been the subject of many articles even:

https://www.businessinsider.com/costco-store-layout-how-to-g...

https://www.npr.org/sections/money/2015/09/25/443519599/epis...

Surely, you're joking?! What if you want to actually see the Flugelfluffer assembled before you purchase it in a flatpack? (maybe you want the white one? no, wait, the natural one) That entails going upstairs and walking around the whole circuitous path through every staged bedroom, dining room, kitchen, living room and bathroom just to find the damn Fluggelfluffer. Which is downstairs. In aisle 47C.

If Costco has the piece of furniture, its either in the middle display area or on the furniture aisle. That's it.