I don't think I'm an expert on the matter 😅, but I will try my best at an educated guess:

• Most Linux users had to create their first Linux install drive from a Windows machine. As such, they were most likely inclined to use something else instead. Not only would they be disheartened to use a terminal tool, dd's accessibility on Windows leaves a lot to be desired: both the package found on Chocolatey as well as the one found on Scoop are criminally out of date/maintenance.

  Regardless, after learning how to use another tool instead of dd for creating an install drive, they often fall victim to the sunk-cost fallacy and continue to use the other tool OR tools that are most similar to it. Letting dd slide for the foreseeable time...

• dd, while absolutely functional, is relatively bare-bones:

  • it does not download ISOs for you
  • nor does it checksum them to see if you got the right one
  • nor does it give you the functionality to put multiple bootable ISOs to the same drive
  • it comes with no guardrails; as such, destroying your own system isn't out of the ordinary. I can totally understand why some people would be hesitant to use something as such
  • it only offers a TUI while the vast majority seems to favor a GUI instead

  If someone would like to use a tool that does any of the above in addition to making an install drive, then dd simply falls short and is simply ignored/dismissed in favor of any of the viable alternatives.