I think there's a strong correlation. We did gain a lot in security and simplicity with the App Store model. Lots of people that would never install apps on Windows or Macs, due to fear and ignorance, do so regularly on their smartphones. Moreover, they upgrade their OSs and pay with credit cards, etc.
On the other hand, those same people had folders on their desktops and managed files reasonably well. And now that even got a bit more confusing on the desktop, especially with MS/Apple insistence in selecting One/iCloud drive by default.
I don’t want to assume ages, so: there was a time way before the app store where installing an app on a mac was as easy as clicking download and extracting the “file” (it was actually a folder, just like current mac apps). Trying it out only needed a double-clicking on the resulting icon.
No install script, no pkg files, no hidden prefs, nothing.
Want to uninstall it? Drag it to trash.
It was only when Apple started to be affected by mac piracy that they started down the road of restricting everything and when they started making real money selling their own content on their own platform (music then movies through iTunes) they hit the friggin gas.
That’s still how I install 95% of Mac apps? (.dmg) I don’t think the Mac App Store is even that popular. Rarely is an app exclusively there, though times might be changing. About 5% of things come as .pkg installers but usually in a situation where it makes sense.
Default macOS will still check for Apple’s seal of approval on software, but this is done by developers signing their distributed app.
There's lots of software that is only distributed in the App Store, which can't be used without an Apple ID (even for free apps), which requires giving Apple a phone number and email address (and the App Store app uploading your unchangeable device hardware serial number).
Some apps, like Wireguard, can't even be installed outside of the App Store, because Apple won't sign the entitlements they need to run outside of it.
On the other hand, those same people had folders on their desktops and managed files reasonably well. And now that even got a bit more confusing on the desktop, especially with MS/Apple insistence in selecting One/iCloud drive by default.