There is nothing magical about 6 feet that prevents SARS-CoV-2 from spreading. It is present in respiratory secretions, which can travel further than 6 feet and remain infectious, especially in enclosed/indoor spaces. Speaking loudly releases more of those secretions. https://twitter.com/tedcruz/status/1328547744584183809

Every safety measure health officials have been advocating for are additive. Masks, distance, hygeine, ventilation, etc. can all act together to reduce risk. There is no singular silver bullet to eliminate risk, hence we push for multiple risk-reducing activities.

A mask alone doesn't eliminate risk, it reduces risk.
Distancing alone doesn't eliminate risk, it reduces risk.
Hygeine alone doesn't eliminate risk, it reduces risk.
Ventilation alone doesn't eliminate risk, it reduces risk.

Added together, risk approaches zero.