Surveillance will not simply disappear if the NSA stops doing it. Other federal agencies engage in surveillance and would simply increase their own surveillance and Congressional support would be high. This is proven by two facts:
(a) Surveillance is politically popular
The Verge, May 14, 2020, https://www.theverge.com/2020/5/14/21257782/surveillance-bill-congress-senate-pass-usa-freedom-reauthorization-act
The USA Freedom Reauthorization Act lets law enforcement collect “tangible things” related to national security investigations without a warrant, requiring only approval from a secret court that has reportedly rubber-stamped many requests. It passed the House of Representatives earlier this year, but it stalled in the Senate during the start of the coronavirus pandemic. Today, senators approved it with 80 votes for and 16 votes against, according to The Hill. The House of Representatives will need to approve the amended version of the bill before sending it to the president’s desk.
(b) FBI engages in racist surveillance
ACLU, 2020, Mappimng the FBI: Uncovering Abusive Surveilance and Racial Profiling, https://www.aclu.