Consumer phones in regional areas are still an issue. As @baku said, 3G has better range than 4G (which has better range than 5G). If someone in the middle of the bush, or on a country road needs to use their 5G phone, they may not have coverage.

I have a friend that had to drive 10km with a cracked skull, ribs and broken arm and leg because he didn’t have coverage on his farm. He now has 3G coverage, but not 4G.