Id have to say the GPS has had both the most positive and negative impact on hunting in my life time. I recall the days where few people wandered very far off of roads or maintained trails. With a map, compass, and some dead reckoning it wasnt hard to get away from folks.
Satellite imagery has had a similar impact, as well as satellite phones, SOS beacons, satellite internet, ect…
For that reason I think if I could take back only one hunting gear invention it would be the satellite.
Non hunting would be farming. Farming and its artificial production of food has allowed the human population to far exceed the carrying capacity of this planet and with our overpopulation we destroy the habitat and the wildlife within it. As strictly hunters and gatherers the natural checks and balances would keep our population under control.