Thanks for the security lesson - I've been in IT security for 30 years and obviously didn't know any of that!
The problem is that most people do NOT make informed choices with the technology they use daily. For example, do you use cash or plastic when buying fuel? If you use plastic, 'they' have a pretty good idea of where you go, even if your GPS appears to be turned of on your phone. 'They' also know fairly accurately where you travel and when, and perhaps what you do (if anything) when you get there. 'They' can also track your movement by the cell-towers your phone connects to.
As for all those migrating from WhatsApp when the announcement was made, what percentage of those do you think have Alexa, Cortana, Bixby, or Siri running on their phones, Smart TV's, Bluetooth Speakers and Soundbars etc? Probably in the high 80%-90%, and yet one media panic story made them concerned about giving data away? People under the age of 50 and perhaps even older than that have already let that horse bolt, because the technology has become part of them and they can't survive without it. I know some very intelligent people who are oblivious to the dangers of having Microsoft, Apple and Google listening in to every part of their lives, and yes, quit WhatsApp for Signal and Telegram, but what's your point? Every facet of our lives (almost) involves giving away information to someone.
I think we've gone a little of topic here, so I'll stop now!