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.
5g didn't bring the widespread adoption of everything being connected that it was sold as, but it's way faster than 4g and definitely worth it.