I was assuming it was actually all set inside IKEA. :P

A similar longer story is Walking to Aldebaran by Adrian Tchaikovsky. If you like the vibe of exploring a place which is nothing forever it nails it.

https://en.wikipedia.org/wiki/Walking_to_Aldebaran?wprov=sft...

I was also thinking of this story around the Backrooms lore (since you can find references that it is infinite or planet-sized repeating). Of course I couldn't remember enough to have it pop up on Google or ChatGPT. Grateful that someone posted it.