It is. Very complicated. The streets are so narrow that GPS signals are blocked, but you can reacquire satellites in the piazzas.
In general, forget maps in Venice. You have to be there too long to know the zillions of tiny streets. Instead, just know you want to go east or west or north. And go there. The only things to see are San Marcos Square and the big tourist bridge. Then go down and watch the shipping.
But if you must have a map, last time I was there (very long time ago) the cyber cafes had printers and you could print one out for a few pennies.
Ooops, I left off the suggestion. Compass. Just use a compass. Then go the direction you want. The maps are really hard work for just the few days one is there.
I am an old farm boy, so that is what I did. I knew a few landmarks, and kept myself aware with directions I was going. There is an app I have on my phone that work as a compass. Yet, when in a very large city, the GPS works to keep the walking to a minimum. There is value in using all these things together.
What is funny though, is travelers are for the most part dependent on Apps, Reviews, Reservations, they do not even try to make these decisions using their own mind, they are very needy, therefore need to stay where other travelers are going. The are not going to go to Africa, unless they are on a tour group, or volunteering. They are not independent.