Influenza starts being contagious a few days before symptoms start and stops being contagious a few days before symptoms end, so yes. But the profile for SARS-CoV-2 is particularly front-loaded compared to other viruses where peak infectivity is basically right as symptoms appear. With many other diseases if you catch all symptomatic cases that's enough to drive R well below 1 and from a public health perspective that's all you need.