I'm most certainly not opposed to saving lives. But we can't just mindlessly approve whatever "solutions" the government comes up with. Some "solutions" are bound to do more harm than good, and mass-surveillance is a prime example considering its potential for abuse. Just as people die from disease, people also die from tyrannical governments. Even if we assume that your government, however unlikely, would forever continue to wield its power wisely, other governments wouldn't care. If we justify the use of mass-surveillance, we would give other tyrannical governments a free pass and more people would be killed or tortured as a consequence. But unlike pandemics, time won't cure tyrannical governments.
Well, I love the positive attitude implying time will cure pandemics. Cure, in the sense that all things come to an end, the way all bleeding stops, yeah.
I'm currently working as an infectious disease researcher for a state with a lot of political turmoil, and I'll have the be honest, my (profesional) opinion doesn't matter. No single recommendation we have made has had any bearing on the action of our state. These opinions we (you and I) have are moot.
Just to be clear, I'm not dismissing the devastating effects this pandemic has brought. More lives will continue to be lost for the foreseeable future and it will likely have lasting economic implications. But if governments around the world go forward with mass-surveillance, it would be 9/11 all over again. As a direct consequence of 9/11, many innocent lives have been lost. But it's the policy decisions after the incident that has had an even more lasting and devastating effect on our democratic society. People need to keep these things in mind, especially in times of emergencies.