Yeah, the idea that any act is irredeemable - or that dying is required for redemption - seems to spit in the face of the core message of the franchise…
I don’t really agree. If Vader survived ROTJ, and Palpatine got redeemed, maybe I’d agree with you. But I think that Ben needs to have some kind of punishment for his actions as Kylo. It’s not like he’s technically dead anyway, so I think his theatrical fate is fine. Especially with Snooker’s ending concept removing the “Rey ends the movie alone” aspect.