let his family live and instead have written a story about living in diasporas

Given that Discovery had plenty of Afrofuturism themes at this point in the story, this really seems like an obvious go-to for where to go next. Booker's homeworld wasn't perfect, but it was more perfect than anything else going at the time; losing it was a tragedy that really needed a better epilogue. Rebuilding that place, or helping his people find a new home (probably with the Trills), is a very compelling arc and would have seen the character come unto their own. We really should have seen Booker find a place among the Federation delegates by the end of the series.

https://en.wikipedia.org/wiki/Afrofuturism