I'd argue the UI is simple. You zoom into a place and it offers to download. Like all maps you can click to zoom to your location and that will trigger the correct download too

I travel a lot so download more than most and the UI is simple, it's just offline first not online first. The video creator seemed to have an ideological issue with that and didn't try but when they did, they liked it. I find videos like this infuriating though so probably missed some points.

It's not impossible an initial modal could help here but I've used it too long to know and it's pretty easy to click through to report a bug for anyone reading this that is new to the app and was confused but still remembers what would have helped