I often hike by myself and, in general, try not to depend on other people having things unless pre-arranged.
I certainly use phone apps--including the Ordinance Survey app in the UK, which is very good. But if I'm hiking in an unfamiliar area, yes, I also do carry a map and compass because that seems like a low cost and effort backup. I'm absolutely not arguing against using a smartphone app as primary navigation. But I do also encourage having backup.
Yeh I often go solo and after a few experiences, particularly if its unfamiliar, I try to make sure to have a charged backup device with routes etc loaded.
Similiarly I am not arguing against people using a map and compass, but I think the current advice which is entirely focused on map and compass with little guidance for phone users (which if it exists, is always caveated) has a lot more to do with outdoors peoples notions of technological purity and less to do with public health
I think we're actually in mostly violent agreement,
The ten essentials or whatever you want to call them are probably rather outdated.
I still think throwing a map and compass in your pack and having at least a bare minimum knowledge of how to use them is useful insurance in an unfamiliar area. But understanding mostly simple processes/backups for GPS is quite important as well. Details vary by circumstance/weather/etc. but simple steps in terms of downloading maps/having backup chargers/even a backup device/etc. are useful and I don't think have generally made it into basic hiking safety advice.
It's really hard at this point to credibly argue that "the ten essentials" don't include a smartphone.
I certainly use phone apps--including the Ordinance Survey app in the UK, which is very good. But if I'm hiking in an unfamiliar area, yes, I also do carry a map and compass because that seems like a low cost and effort backup. I'm absolutely not arguing against using a smartphone app as primary navigation. But I do also encourage having backup.