Regarding your first point, I'm not sure if that's true, I think they use low frequency spectrum around 900MHz (just like LTE) as well, not just the 2000MHz+ to GHz spectrum in densely populated or visited places.

Also, as far as I'm concerned, the latency gains are much more interesting as the ludicrous speed, and then not even exclusively for phones and new types of apps, but for IoT as well