In my younger and more vulnerable years, I most remember the only place I could find D&D game books and box sets was a small bookstore on the main drag in Wisconsin Dells. When we went on vacation/work on my grandparents' summer cottage, I usually ended up grabbing a module or "Complete Guide to..." Closer to home, Waldenbooks, Crown, B. Dalton, and Krochs and Brentanos in the malls only had novels as far as I recall. I may be misremembering though.
Then I discovered the Gamers Paradise at a mall a little further from home, and it was like opening the Library of Alexandria...but you know, I could buy the stuff!
Today: 2 Targets, a Meijer, and 3 Wal-Marts in my typical errand-running radius. Meijer has the Essentials Kit in the boardgames. I remember seeing the 2014 core books, the Planescape box, and the Spelljammer box there in the past, but that has to have been at least two years
Similarly, I remember seeing 2014 Core and other WotC books at Target, in fact, one of them still has a shelf display wrap with them on it! But actually in-stock? One Target has weird aisle in the Toys departmemt that has some of the NECA figures, the TCGs and sportsball cards and paraphernalia, high-end Lego, squismallows and other stuffies, and some D&D: Chesex dice, Stormwrack and Essentials boxes, minis (the Circle app says the have 50th Anniversary, Fizban's Treasury of Dragons, and Monster Menagerie II are in stock right now), "Worlds and Realms," and some 3rd Party maps books/"The Gamemasters Guide" books. The other Target has some of those books on an endcap in the Books department, and Stormwrack and Essentials in the boardgames. One Walmart has nothing as far as I can tell, and I'll swing into the other two over the course of the week now that I'm curious. The local Barnes and Noble is standard: good selection of WotC/Wizkids stuff, some 3rd Party, and really no other TTRPG titles as far as I have noticed (but man, they went ALL IN one Battletech and have not put any of it on clearance!)
We're blessed with THREE local game stores, a Games Workshop, and a Gamestop in the same radius as those big-box stores (and I'm not TOO far from Games Plus--IYKYK, as the kids say), so I'm lucky enough that if I want to go game shopping, my dice bag runneth over with options. (I know how lucky I am.)