I don't disagree it would be nice if you could control the fans the way you want.
The RX580 used to turn the fans off under no load. When the 2019 drivers came out they mad it so if you use a manual fan setting there is no way the fans ever cut off.
One way some get around this if you don't mind losing the Radeon Settings and related software is to only load the AMD driver part.
You can do this by letting the driver unpack to the AMD folder, then cancel the install.
Then from device manage choose your GPU and update the driver by pointing it to the AMD folder and it only installs the driver.
Then you can just control your fan how you like with Afterburner or Trixx for instance. Just don't use those 3rd party utilities and Radeon Settings as they are known to conflict.