Prigozhin's rationale for this episode seems to be intense annoyance that he wasn't getting respect.
And now - as he believes - he's got that after a show of strength, everyone can go home and pretend it never happened.
It's insanity. Just bonkers. All of it.
Some Ukrainians I know tell me there's local suspicion that was a feint or a ruse to see where Ukraine would attack. It's an interesting idea, but that seems a lot of effort and drama for a very small reward.