Yodobashi Camera in Japan, has got to be one of the best camera stores in the world. If they don't have what you want, you probably don't need it.
That's the one. Apparently it's huge. Must visit one day.
https://www.capturemag.com.au/news/capture-visits-the-world-s-largest-camera-store-yodabashi-camera
Japan also has huge used camera shops too. Those, I would probably find more interesting tbh.
It now sells a lot more than camera gear. I saw one video, there was more about massage than cameras.
Due to the massive crash in camera sales their previously major Akiba store now has shrunken their possibly earlier 4 or 5 floors of camera gear to now one floor.
https://www.yodobashi.com/ec/store/list/en and click the floor guide of the store you like and wait for the auto translation of the page.
That seems to be the page to explore the floors of every store but for some reason I cannot access any Yodobashi pages at all right now. OK a FireFox foulup, accessible via Edge.
The Akiba store camera gear now all on the 3rd floor along with a lot of other unrelated stuff.....
Oh the heady days of 2009 and 2011 when I first visited, truly magic store to get lost in, now a feeble version of its old glorious self as far as cameras are concerned.