The point is that they're using an off-the-shelf icon kit with some native dialogue forwarding. By this definition, VS Code is also a 'native' app, which we know to be untrue.
Frankly, I think the MacOS HID has been dead since Mojave. At some point, developers realized that Cocoa wasn't enough for most apps, and it was an awful lot of work to put into an app that would only be used by a fraction of their customers. Currently, the definition of "native" on MacOS is that it uses loosely the same keyboard shortcuts as your other programs, and if you're lucky then it integrates with your global menu. In the age of webapps and cross-platform development, there's simply not a way that MacOS' approach works. Even niche toolkits like GTK solved this problem better than Apple, which makes it even more mind-blowing when I see Mac developers defend their build system.
Walled-gardens lead to sticky situations like this, where volunteer-driven efforts are more developer friendly than first-party offerings. I weep for the Xcode users who don't know what it's like living on the outside.
I respectfully disagree that GTK is more friendly than AppKit. It may be truly strictly from a cross platform perspective, but AppKit is still unbeaten in variety and capability of UI widgets, especially if front end web is the point of comparison. Just to get an interactive table view that’s comparable in features to NSTableView on the web you’re looking at duct taping together several libraries or reinventing the wheel yet again and writing the whole widget yourself. GTK and Qt better than the web in this aspect but still not as good (custom widgets are still frequently necessary with both toolkits).
AppKit only comes up short in that it’s not built to have its appearance changed dramatically and of course that it’s tied to macOS. If you need cross platform that’s a legitimate limitation, but as noted before brand driven UI design is far from a need.
Frankly, I think the MacOS HID has been dead since Mojave. At some point, developers realized that Cocoa wasn't enough for most apps, and it was an awful lot of work to put into an app that would only be used by a fraction of their customers. Currently, the definition of "native" on MacOS is that it uses loosely the same keyboard shortcuts as your other programs, and if you're lucky then it integrates with your global menu. In the age of webapps and cross-platform development, there's simply not a way that MacOS' approach works. Even niche toolkits like GTK solved this problem better than Apple, which makes it even more mind-blowing when I see Mac developers defend their build system.
Walled-gardens lead to sticky situations like this, where volunteer-driven efforts are more developer friendly than first-party offerings. I weep for the Xcode users who don't know what it's like living on the outside.