The Covid/cancer angle got the most attention in the mainstream press, but among some of the theorists I follow on Twitter, the general take is that 5G does not really have much application as a consumer technology (do people really need to be able to download 4K movies in 2 minutes on their mobile phones?). It does, however, have numerous applications in ubiquitous high-res video surveillance, autonomous weaponry, and the like.
Not familiar in the technology at all but was there not promise of better cars with 5g capability like the ability for all of them to be coordinated and send messages between cars like described in this article
https://www.zdnet.com/article/connected-cars-how-5g-and-iot-...
There are indeed some legit consumer uses one can point to with 5G, but at the very least they all tend to come with the implication of more surveillance as one effect. For example, the fleet of cars all pinging messages and coordinating with one another implies that their exact location becomes knowable at all times to some centralized network node.
Sounds like you might have an interesting take on what creates a conspiracy theorist? I don't meet many in my life (and I don't follow any, like you), but it seems they are becoming ubiquitous.
Speaking personally, I started out as an avid Skeptic Magazine reader and conspiracy doubter, but became interested in conspiracies after watching those inclined to believe in them accurately predict in real time (including in HN comments) that Jeffrey Epstein would die in prison before he would be allowed to come to trial or testify against the numerous wealthy & powerful people with whom he was associated. The media then proceeded to immediately circle the wagons and insist that anything other than 'it was a lone suicide' was 'baseless conspiracy theory.'
I imagine for most conspiracy theorists it's a similar process. They see some evidence of our society's widespread institutional corruption and the mass deception which is deployed to protect it, and begin looking for the truth in alternative avenues. Unfortunately it is then very easy to exit the first hall of mirrors into another one, like QAnon.