Yeah, I recently updated to Catalina. I had to Google to find the download link, but it was still available from apple.com
Wikipedia shows the exact version number of the latest releases for each.
To be honest, I’m probably not going to upgrade again at all until the new MBPs seem stable enough for me to buy. Nothing in Big Sur or Monterey seems compelling enough, apart from M1 support and access to iOS apps, for me to risk the disruption.