A couple of dudes from Cloudflare gave a really cool Black Hat presentation "Monsters in the Middleboxes: Building Tools for Detecting HTTPS Interception". Who would have thought that HTTPS inception was so prevalent? They even Open Sourced a detection tool. Here are the sound bytes from the presentation:
Now imagine, this within a smart building with 5G connectivity and IoT devices peppered all over the place, with fabric of the building or a Hospital.