My daily work is in forestry, as a brush cutter -- occasionally, GPS would be necessary (unavoidable even). For 95% of the cases, though, I've found a workaround by postponing the map-related tasks (e.g. making sure I understand the borders of a particular forest subcompartment correctly) to the next day and hand-drawing the shape of the subcompartment from an online map to a piece of paper. With the drawing in hand, I can usually accurately confirm the borders by visual observation. Once more, this probably only works for simple blue collars, not for guys that need to do more on-site planning.
Other than that, I occasionally miss a tolerable camera (for digitizing expenditure checks) and QR code reading ability.
All in all, living with old dumb phone is fun. Zero cost if you break it or ruin it in the forest (mud!). I hate my current Nokia, though -- but can't ditch it because it still works, lol. I still miss my Nokia 3310 (the original one), which I used every day for 12(!) years in a row, starting in around 2001 as a high school student and finally letting it go in around 2013 when I was a young father. It was one hell of a phone.
My current favorite oldscool dumb phones are the "senior phones" with huge buttons. This ZTE s202 was really enjoyable to use (belonged to my grandpa), and the no-bs design somehow feels really elegant: https://i.hinnavaatlus.ee/p/1200/99/43/S20220must__6ee8.jpg