It seems like they took Kursk without losing much.

Pretty sure they lost at least 3 columns trying to take some towns there.

Now they have a bargaining chip for peace talks...

No they don't. For the territories they occupy to be a bargaining chip, the territories would need to be strategically important enough for their capture to threaten Russia's ability to fight this war (they aren't) and Ukraine would have to be able to guaranty that Russia can't get them back by fighting and is forced to negotiate to get them back (highly doubtful given that Ukraine can't even stop Russian advances in their own territory, only slow them down at best).

...and possibly diverted attention away from the main front.

Last I've heard Russia haven't even diverted troops from the main front line in Ukraine, so no, it didn't even achieve that. Which makes sense when you know that Russia has way more manpower and equipment than Ukraine right now, this isn't the stare of the war when Ukraine's army was motivated and received billion dollars arms shipments every week anymore.

Forcing the enemy army to split over more front lines only works if you have the resources to maintain more front lines better than your enemy can. Which is why it's Ukraine who are getting stretched thin by their own shenanigans here, not Russia, the Kursk invasion was objectively not a smart move.

The western reporting may also get under Putins skin.

That's cute, but war is won with steel and blood, not twitter ratios. "owning Putin" is at best going to be a very short moral boost that's only gonna last until the soldiers on the front line notice that they are still getting shredded en mass by Russian shells all the same as before.