We hike in the Alps and carry a cellphone for emergencies, either in case we need help or (more likely) our elderly parents need to reach us. While cellphone coverage is amazingly good even on remote trails, there aren't any WiFi hotspots out there
That may slowly change because even some alpine club huts now have Internet but that could take years. And even so, once you leave a hut there's no WiFi. So we'll need a global SIM for the foreseeable future even though we hope we won't need to use it much.