One of the biggest gripes people have with Android is updates of the operating system. Because Google only provides the base OS, which is then customized by the handset manufacturers and then possibly also further customized by the carriers. It’s hard to predict when or even if your phone will get an update. The Google Update Alliance was supposed to fix all that. Unfortunately, that hasn’t happened.
I have an original Droid from Motorola on Verizon. I haven’t received an update in close to two years. Because of the age of the phone, I never will. But even people purchasing phones today are likely to never get an update. That just seems wrong but it’s explainable given the chain the OS goes through to get to you.