The main issue is that there is no reason for companies like Facebook to fully adopt it, since it doesn't benefit them and there is no outside pressure forcing them to do so.
May be I'm the only one but how is the parent referring to Differential Privacy? Differential Privacy is "one way" to achieve privacy. The parent comment talks about a different standard for privacy the moment computing power increases.
The main issue is that there is no reason for companies like Facebook to fully adopt it, since it doesn't benefit them and there is no outside pressure forcing them to do so.