It also has no Windows installer - it's a bare zip archive. In order for all the existing software that expects Java installed to find it you need to set severa

It also has no Windows installer - it's a bare zip archive. In order for all the existing software that expects Java installed to find it you need to set several environmental variables and registry keys. AdoptOpenJDK has an installer that can do all that for you, making it pretty much a drop-in replacement for the old JDK and JRE downloads. There's almost no way for anyone who wants to run older software that needs Java to discover AdoptOpenJDK though.