In reply to JIMBO:
> If a gps runs out of battery you can just pop in two new AA batteries unlike your phone...
As above, if your phone battery runs out, you can pop in a power bank and recharge. Some phones still have replaceable batteries, although the obsession with wafer-thin phones has limited that in recent years.
You don't have to have GPS on all the time. You can easily turn the GPS receiver off and back on when you want a fix. Between such fixes, you can navigate pretty much conventionally with the map displayed on the phone. If you do this at at least a four hour interval, and leave it enabled for about 15 minutes, it will retain an up-to-date ephemeris, allowing a warm fix when you do need it.
You only need the GPS on all the time if you want to log your route, or are obsessed with the likes of Strava. Even then, most decent mapping apps will automatically control the GPS receiver, turning it on once every few minutes to get a fix to log, and then turn it off ('track log rate' or similar setting). How fast are you moving, and how accurate a route log do you need?