Assume you are being watched (or listened to) at all times. Because it could be true.
Surveillance can be installed in your phones, iPads, Alexa, laptops...even hotel rooms are easily and quickly bugged. Perhaps you have nothing to hide. Most of us have nothing to hide. But that misses the point.
Today the government monitors for illegal activity. Tomorrow, however, they could flip the script and start monitoring for enemies of the state. Are you an enemy of the state? Maybe you're a journalist. Maybe you subscribe to a particular religion. Maybe you're skeptical of your government's leadership. It is quite easy to be arbitrarily considered an enemy of the state. However, by that point the surveillance genie would be impossible to put back into its bottle.
Privacy is a human right. The more difficult it is to identify and target people behaving unfavourably, the more a government must focus on people committing true crimes instead of its pet enemies.