In Australia on my 13,000+km ride I used a combo of paper maps and
HEMA Offline Topo Maps.
Paper maps are handy on long trips as when you're done with them,
you can pass them on to someone else; less luggage.
I brought my iPhone with me anyway but would leave it on aeroplane mode
or just keep it off entirely if I knew where I was going.
Battery lasts ages (several days) like that.
Offline maps on the smartphone are handy for planning.