1. "Wiretapping" is the wrong conceptual model for what is proposed and implemented in modern systems. "Vacuuming" might be a better term.
2. This is a power grab, not merely an attempt to maintain equivalent present powers. As people live increasingly more of their lives on or impacted by virtual systems, the power to monitor and abuse whole societies becomes significantly larger. If you have any doubts about this, imagine it is the North Korean government with the technology.
3. Private communication, the minimum of freedom of expression and closest to thought, of any kind is never a hindrance to prevent crime or its investigation. A crime and everything leading to its implementation (and after) has many consequences in the world. It is these effects that are critical and required for crime prevention and prosecution. If there was a technology to monitor everyone's thoughts at the same time, would you use it as part of the criminal system?
4. The costs are orders of magnitude larger to setup, grow and maintain such monitoring systems indefinitely instead of targeting crime prevention and investigation. That's your taxpayer money being spent.
5. If after all the above, the inevitable result is still for governments to have the potential ability to access all communication anywhere between anyone at any time, then to reclaim individuals' rights, they too have a powerful incentive to seek and create systems that achieve the opposite, including encryption. This will occur regardless of law, and the deeper the loss or perception of loss of private rights, the more widespread it will occur.
In short,
"Those who desire to give up freedom in order to gain security will not have, nor do they deserve, either one."