GPS devices on bikes falls into the catagory of helmets and viz vests. My view is that you make your own mind up and let everyone else get on with what they want to do.
I like maps. I am an ex army map reading instructor. But I also like GPS devices and use many of them on a regular basis. I think
Ordnance Survey maps in the UK are some of the best maps ever made. But you can get so much more information from using a route making app such as Ridewithgps. A track on a map will just stop. Giving you the impression that you cannot go any further. A route app will allow you to go into satellite view and see if the track continues. It may have heatmap where it will show if anyone else has ridden there.
Plan a route on an app and you instantly see the elevation. You can add your own points of interest and customise your own notes and print them all out into a route booklet.
I use my phone, a Wahoo Bolt, a Karoo 2 and a Garmin 1030. They all have plus and minus points. But if you practice with them and try to make them go wrong. You soon end up riding tracks in your local area that you have never come across before and that probably do not come up on a map as something that you try to ride.
I enjoy sitting at home on the PC planning my next ride and finding new places. But I also like sitting on top of a hill with a map and picking out points of interest. But there is little doubt that following a route on a gps is far easier and quicker than using a map.
Both have their merits.