Start with "Why should we go back?"
The fact is there's really not a reason. We've been there, done that. The cost to send people to the moon is astronomical (lol) but the value to civilization is minimal at this point.
Honestly, NASA spending more time exploring Mars has been more beneficial.. Just wish we found something more up there, but hopefully in time.
I wish we could go to the moon again too, I just don't see a purpose, and that's kind of why we did that, and stopped.