Different meats have different amounts of connective tissue that need to break down, the more they have the longer they take to become pull-apart tender in a slow cooker.
The amount also influences the final texture of the meat- the more it has the more gelatinous and moist and amazing it tastes.
Chicken is fairly low in these things vs say short ribs. So while chicken will most certainly break down and tenderize over a long slow cook, it just won’t have the same texture when it is done.
You’ll have better luck with thighs and drums that have more connective tissue.
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