Assuming that surveillance works (and I'm not really sure it works well) then the alternative is terrorism and crime. I agree we need some level of surveillance, but the question is at what point do the risks of the surveillance (suppression of democracy / dissent, self-censorship, loss of privacy / liberty, concentration of rich data for misuse by bad actors, etc) outweigh the risks of terrorism and crime? Just because we can bring terrorism and crime to zero with max surveillance, doesn't mean that it's in the best interest of society to enable such a system.

Personally, I'm willing to accept a level of risk from terrorism and crime if it means that I get to live my life the way I want to without being constantly monitored by government.

Regarding checks and balances, it's extremely hard to have robust authorization when the group calibrating and performing the authorizations is the same group or adjacent to the group who wants to look at the data. To do it well you need true, apolitical, independence between gatekeepers and users, and users can never be in possession of the actual data because access control can be easily bypassed if this is the case. We have never had that in this country, countermeasures against misuse always seem to be non-transparent and policy based rather than technical (ie secret courts and warrants that no one can actually audit), and data is repeatedly misused over and over with no consequences (eg parallel reconstruction, people spying on partners, people spying on celebs, etc).