It is one datapoint among many, but I found it interesting because it is based on careful biological experimentation and directly compares immune response from vaccination and prior infection. Another relevant quote: "Importantly, the vaccine-elicited antibodies targeted a broader range of places on the RBD than those elicited by natural infection." This is not an intuitively obvious result.
But, since it was asked, here are more studies that support the broader point:
* https://www.contagionlive.com/view/immune-response-from-mrna... describes a study directly addressing the question, and with impressive results.
* https://medicine.wustl.edu/news/covid-19-vaccine-generates-i... didn't directly compare against prior infection, but this is discussed briefly and there is strong support in favor of protection from vaccines.
* https://www.medpagetoday.com/opinion/marty-makary/92434 is a discussion with a virologist (not peer reviewed science).