Sample group of me, my wife, and my son. We see symptoms die down in 24-48 hours. Its very clear they work, especially in my case where I've always had a long hard struggle fighting off infections.
I do make an effort to get more Vitamin D in the winter, which has been helping me avoid getting sick, but not recover faster.
>Wondering what my body would naturally do with those five days
Strep can become deadly in children. Invasive strep has a significant mortality rate, and that's with treatments. If you think you have strep you should get treated.
Also, I find it amusing you consider drugs unnatural. We are a tool using species, naturally. Developing and using drugs is in our nature.
Lastly, this is the same reasoning anti-vaxxers have, so I'd be careful here. It can lead to some really bad outcomes.