Most researchers don’t share their data. If you’ve ever read the words “data is available upon request” in an academic paper, and emailed the authors to request it, the chances that you’ll actually receive the data are just 7 percent. https://twitter.com/thej/status/1585154573156876290The rest of the time, the authors have lost access to their data, changed emails, or are too busy or unwilling.
https://www.wired.com/story/covid-19-open-science-public-health-data/