Why `getPackagesHoldingPermissions` returns only system packages?

I want to list all apps that use internet, I see this feature from the app WireGuard, this is how it does(link to the code):

    val packageInfos = getPackagesHoldingPermissions(pm, arrayOf(Manifest.permission.INTERNET))

    private fun getPackagesHoldingPermissions(pm: PackageManager, permissions: Array<String>): List<PackageInfo> {
        return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
            pm.getPackagesHoldingPermissions(permissions, PackageInfoFlags.of(0L))
        } else {
            @Suppress("DEPRECATION")
            pm.getPackagesHoldingPermissions(permissions, 0)
        }
    }

It shows all apps, including non-system apps like whatsapp or any third party apps.

Then I tried this code in my app, but it only shows apps like "com.android.x" and "com.google.x", there are no non-system apps at all. I thought it might be caused by permission, I deleted all permissions in WireGuard's Manifest.xml, and it still works, so I think it's not caused by permission, but why is that?

WireGuard has:

    <queries>
        <intent>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent>
    </queries>

in its manifest, to address package visibility. My guess is that you do not.