I'm absolutely not childless. I was a full-time wife and mom for a lot of years.
I'm sorry you feel so defensive and feel such a strong need to justify your choices rather than contemplate the possibility that some people who disagree with you have a fine parenting track record, have been at it longer than you and have thought a great deal about some things.
I wish very much that I had a means to educate more parents. But I am no longer a full-time wife. I have bills to pay and I still support my adult special needs sons and the world has made it abundantly clear that the things I know and wish to share are not worth money.
But in a nutshell, there are hidden costs to the kind of approach you are taking. It is akin to the saying "Going to war to preserve the peace is like fucking to preserve virginity."
I chose to not tell my children "There are bad people out there that will want to do unspeakable things to you, so you should be afraid, very afraid." because I felt that would rob them of the very innocence I desired to protect and preserve. Instead, I taught them by example what genuine respect looks and feels like by setting the standard for that with how I treated them.
They were taught they could say "No" to people -- including me -- for things like hugs and kisses. They were taught it was their decision, not mine.
But I would happily play enforcer. If someone didn't respect their decision, "Come get mom."
My oldest inferred based on his experiences that protecting himself from a bully with violent force was completely reasonable when he was at school and getting Mom was not an option. He didn't even feel it was noteworthy and I learned that story years later.
Rumaging through your daughter's phone sets a precedent that future boyfriends or husbands can take advantage of to her detriment. And there are better policies that achieve the same thing without that.
My sons have been online since they were two and five. I arranged kid-friendly menus to help them find things of interest to them easily with little risk of exposure to undesirable parts of the internet.
They were not constrained. They didn't want such exposure. They were happy to stick to the things I helped them access that met their needs without having to be hassled with this other stuff.
I know this is a touchy subject and you will probably be offended. But it's touchy because both sides of the argument are personally invested, not because your personal investment somehow trumps mine.
I was molested and raped as a child. I thought long and hard about how to protect my children not just physically, but also emotionally and psychologically. They are old enough that I've gotten to see the fruits of my labor.
Unfortunately, no one wants to know what I did. I'm just a woman, so I must be stupid or something.
We all have our bag of rocks to carry in this crappy world.