Tbh Chiellini has no business starting games anymore more so than Bonucci if you ask me
Actually if Pirlo prefers to start injury ridden Chiellini ahead of De Ligt, that would justify the nepotism argument much more than Bonucci because Bonucci has rarely missed games whilst Chiellini has barely played much competitive football over the past year or so and he's ageing.
In all fairness, Demiral hasnt exactly stepped up to the potential which we all expect in the games he's played this season. I've been very critical of Pirlo but here he probably gets a pass because of a lack of better alternatives. Having said that, the less we see of Bonucci in the future, the better.