Earlier quoted context omitted.
It depends on what your threat model is. If its individuals, local law enforcement, or even national law enforcement (context dependent) you are trying to hide from, you can obtain phones with cash and make it very difficult to link them to you (use a sim card bought with cash and never give out that number, use a VOIP service for your primary number, use an OS that doesn't send back much telemetry, turn off location…
What will happen when hiding even small illegal activities becomes impossible?
I was driving home today and the satnav warned us about driving over speed limit (74 mph on UK motorway). Ok. But the solution to that is technology - and organisation. There are speed cameras on this road. But most of the time they don't take images or don't trigger an action. If every road camera triggered a warning / fine on every violation then speeding would stop in a few months.
Is that something socially beneficial ? Probably. Would it be disruptive and cause great anger and political resentment? Yes.
That is one tiny example but I think that pretty much every criminal act can be detected with technology - it's going to become which one we care enough about to prosecute and which we give up and decriminialise?