The article explain why studies with a placebo branch are important. You have a lot of known unknown and unknown unknown. In particular, as discussed in the article, counting the number of cases/death is hard.
The main problem with the article is that all the vaccines are approved after a RCT were the vaccine is compared to a placebo. For example, look at the slide #6 in https://investors.biontech.de/static-files/53f0968a-279b-4f8... and more details in https://en.wikipedia.org/wiki/Pfizer%E2%80%93BioNTech_COVID-...