It wasn’t a health concern. The only concerns for 5G were long-term practicality, energy and service costs and shorter coverage.
5G was supposed to be made for robots, IoT and wireless home internet.
I haven’t tried 5G, but it seems that the expected speeds would be the same as 4G in early days.
It’s faster but that doesn’t matter to me and 5g is attenuated much more by people and buildings which does matter to me.