Honestly, I don't think it's a culture thing or a CS fundamentals thing.
I think it's the fact that software is 100x, or maybe even 1,000x, more complex that it was just 25 years ago.
Apps are built on so many libraries and frameworks and packages that an average application will have 100x the amount of code. And they're all necessary. A typical phone app is 200 MB, when Word 4.0 was less than 1 MB.
But it's not just the sheer number of lines of code that can have bugs. It's the conceptual complexity of modern software. An app has to have an interface that works with the mouse and with touch, large screens and small screens, regular resolution and retina, light mode and dark mode, it works offline and online with sync functionality, it works in 20 different languages, it works with accessibility, it works with a physical keyboard and an on-screen keyboard, over mobile data and over WiFi, it works with cloud storage and local storage, it goes on and on.
There are so many combinations of states to reason about. When I was building software for Win32 back in 1995, you worried about screen sizes and color depths. That was about it.
Software's just gotten incredibly complex and there's more to reason about and software quality is just going to suffer. Like, I love Dark Mode at night, but at the same time I can't help but wonder what bugs would have gotten fixed if engineering resources hadn't gone into, and continue to go into, Dark Mode for each app.