There are non-radar towers that don't have scopes. They may have a traffic display, or maybe not. They might choose to use a public ADS-B aggregator site because it gives them situational awareness, but they don't use it to provide radar services to aircraft. That's my understanding from listening to a lot podcast episodes with air traffic controllers, anyway. I think it's an unofficial, non-FAA approved kind of thing that can make their jobs easier.

See https://www.faa.gov/air_traffic/publications/atpubs/atc_html... for non-radar ATC procedures.