I have one that is smart, and you are spot on. It was nice to use in the beginning to get an idea of what pressure is recommended and time spent on each section. But I have uninstalled and been running app free for several years now - with zero issues.
In Norway. Technically in a city, but it’s very rural. About 30 minutes of walking with a descent of ~150 meters. Carrying groceries back up that hill is a big test of stamina, so we very rarely do it. We mostly drive to the store.
Your friend is full of shit. 3km is a very long distance for walking to get groceries, and I can imagine that you have to deprioritize heavier groceries all the time due to that distance. I’d recommend getting a bike or electic scooter or something to cover that distance. Basically no one in Norway would have 3km to their nearest store with walking as their only option.