What's The Need To Create Jannah?
beyond imagination does not mean unattractive. We are told that there we will have whatever we like. This is the utmost wish “to have whatever one likes” is the greatest attraction for human beings. Creation of Jannah is to show the bounty of God, prepared eternal blessings for a temporary small test.
Re the freewill, It’s our role in co-creation as designers that necessitated empowering us with free will and jannah (and Hell) is only a control to stop us from misusing it.