Mostly agree, but I wonder if using the phone GPS via Bluetooth would use less power than using the watch GPS. Either way, I doubt that Garmin would implement something like this for a watch that already has GPS built in.
Competitors have this feature and I don't think it's just for fun. The phone has the ability to determine location not only by satellites. Open sky is not always available.
Of course, I wrote about the proposed ideas, but in the neighboring topic, they spent two years fixing an obvious bug with the volume on Apple headphones, so this idea is more of a utopia, but it has a right to exist.