There is some truth to it, but not as pushed. 5G uses more dangerous frequencies. All of the common frequencies have been in common use for decades. Nothing new. What is new is use for end user devices and higher power outputs. Higher power is used because the frequencies are more easily attenuated (pollution, humidity, trees, leafs, rain, etc.). But the power falls off more quickly. But, it means birds which roost in front of the transmitters will be cooked. The prohibited danger zones for humans are much larger now. Most of stuff provided on this topic is propaganda, misunderstanding, or misrepresentation. 5G is a standard for signaling and frequencies and power levels. The signaling is new. The frequencies are mostly old. The danger of non-ionizing radiation is a function of energy density and power. These higher frequencies do not penetrate skin for the same reason it's attenuated by the atmosphere. Now then, certified devices frequently use illegal power levels. Meaning most certified devices are actually illegal for use. Accordingly there is some danger from use of these devices.