I appreciate what they're doing structurally, but sometimes they pull me right out of the story's mood. I'll be deep in the flow of a tense narrative, and then I'll hit a bonus chapter that's a lighthearted, fourth-wall-breaking chat with a side character. It's a different flavor of spice, and not one I always want mixed in with my main course. For me, the 'bonus' material often feels like DVD extras that should be clearly separate, not stitched into the main text.
My reading experience is pretty linear, so when these chapters are integrated into the digital edition as numbered chapters, I can't easily skip them on a first read without risking missing actual plot. I wish platforms had a clearer toggle for 'core narrative only' versus 'full edition with inserts.' They're nice for a second pass, but they can dilute the initial emotional payoff.