Unmounting does not mean the device gets invisible. You could still mount it again by e.g. clicking it. Still it is unmounted and safe to be removed. Disconnecting the device from the system makes it disappear but that is not required for unplugging/ejecting.

This would be a flight mode switch that reliably works. But it also means you are offline, which is no solution to the average “daily” problem of being tracked.

As much as I would love to have a Linux phone, it will not fully help with privacy. The devices are logged into a cell tower and have a unique ID. This alone makes them trackable.

It is not worthless. My understanding is that management only trusts sources that are expensive.