I don't know if there was ever a bookstore that ever had a copy of almost any book you could reasonably be looking for. Maybe Powell's back in the day if you counted the technical bookstore along with the mother ship. Certainly not Barnes & Noble. There are still multiple rows of magazines at B&N today, including ones on Linux, programming, network admin, Raspberry Pi, etc.
The one I go to is the same size as the ones I went to 20 years ago and an order of magnitude larger than the mall bookstores I went to 40 years ago. Although some of that space is taken up by the coffee shop, Legos, and vinyl records.
And B&N itself is doing just fine, and is opening new locations. Borders is the only major chain that failed to adapt. Other large book retailers are also still going strong, e.g. Books-A-Million.
[1] https://www.census.gov/library/stories/2021/12/do-not-turn-t...