The Gamestops in my area still carry a healthy amount of all your mainstream releases and also a lot of smaller releases too, which is nice. But yes, you are absolutely correct; Gamestop is operating on borrowed time that is quickly running out. I've said this numerous times, but I genuinely believe this next generation of consoles will be the last full gen that Gamestop is around for, and even then I can see half their stores being gone by 2025, if not way more. Physical media is essentially dead for music, it's almost there with movies and TV, and video games will soon follow suit. I have no doubt in my mind that Gamestop will be gone by 2030, and they'll likely not even make it that long I'm afraid.
I used to hate Gamestop with a passion and from probably 2007 until 2013 I refused to shop there as a result of a series of bad experiences, them buying out all their competition in the early 2000s, and my loyalty to local, independent game stores during this time. However, my opinion of them has improved more and more since then, and I'm at the point now where it is by far my favorite place to shop for games, even more than independent stores in my area. I go to two locations mainly and each one has really cool people working there, and both still have a good selection of titles. It will make me genuinely sad when neither are there anymore. But as you said, this has a lot to do with physical retail quickly dying out in favor of ecommerce.
I've had a pretty rough couple of years with many of my absolute favorite places to look for games going under, and the thought of Gamestop being gone in the coming years just makes me even more depressed about all of it. I'm starting to genuinely feel old despite being in my early 30s as someone who remembers how important physical media is, and how I absolutely prefer it over having something digital. I know that anyone born after 2005 or so probably has little to no idea what this feels like, and of course as they get older they'll never care about physical ownership, but rather the convenience of just being able to download or stream media immediately from their home. I feel like I've already adapted a little towards this change, but no matter what I still value actually having something I own and that I can touch. When Gamestop goes down I'm uncertain as to whether or not I'll continue to play new games, and if I do it will probably be done in an entirely different manner then how i currently purchase and consume new games.