How do I access my Google Maps?

I happened to stumble upon this section and noticed the option to create a new map
To be perfectly honest, I’m struggling to grasp the utility of this feature—what exactly is the intended purpose behind generating a custom map?
Would anyone be kind enough to provide an explanation?

Check under All if you want to see some examples.

ironcyclist58 said:Take a look under All—you'll find plenty of examples there.

I am sorry, I have no idea what "All" refers to here.

Every time I switch from the OWNED tab over to ALL on that page, it just starts throwing random maps at me.

ironcyclist58 said:Whenever I switch from the OWNED tab over to the ALL tab on that page, I start seeing all these random maps popping up.

On my screen, it just says "you don't own any cards"—everything is completely blank.
I guess my real question is: what is even the point of this card crafting system? It seems much more straightforward to just set a route using the classic method—it feels redundant, doesn't it?