If there are things you want to communicate that you want to remain secret then strong encryption is the only answer. Yes, that too may eventually be broken but the idea is that it will be far enough in the future that it won't matter. I don't think security is a complete myth though it is difficult. If security were a complete myth then bank accounts, cryptocurrencies and many other things would be impossible. Most of us are not (and should not) be posting private things on or via the internet in any form. Not enough people realize that Facebook's privacy settings (for example) aren't really guaranteed or necessarily impressive.
RE: My thoughts on the Internet and technology