If the DCU was a long serialized narrative that still had an end point in mind, I'd say Barry and Kara's COIE deaths were perfect end points to them and I would have left them dead. They ruined the latter's death by exiling her from continuity almost immediately in one of their single dumbest decisions, so that needed to be addressed on way or another.

The lack of any of this ever ending kind of makes any of the deaths for the big name characters impossible to stick. When every character gets resurrected at some point, it's unfair to leave Barry and his fans out in the cold. What they've done with him since the resurrection and what happened to Wally is an obvious source of contention, but I imagine Barry's fans constantly hearing how he served a better purpose dead than alive and that Wally was always the better character must have pissed them off to no end.