I think some people get a little overly hung-up with the whole redundancy thing here.
I'm about to jump from my stand-alone Garmin to a Aoocci thing as I want to use the convenience of Apple Car Play for navigating, music, phone etc.
I'm not planning on keeping the Garmin mounted on the bike.
I have some redundancy with the BMW (un)Connected App sh1t that I could try using in a dire emergency on a big trip.
However, I always take a map book with me.
There are things called road signs.
Funnily enough, the world managed to cope with travel before GPS, phones and electronics were all pervading.
The way some people on here talk about having a stand-alone, dedicated GPS device in addition to your phone-mirroring screen thing is enough to make you think that your air-supply will run out should you have the misfortune of temporarily losing the ability to electronically navigate.
Chill out!