Apple is plenty capable of more aggressive designs, but they are very conservative with a more incremental approach. In my experience, this used to be justified to ensure the next new feature works well. However, since we lost Steve Jobs, their reasoning appears to be more cost-centric, whereby they hold back on currently available features to encourage customers to upgrade more often. It's annoying as hell, but when you consider that Tim Cook was formally Apple's CFO, it makes sense. I do wish that Apple wasn't so lazy when it comes to new features, but there isn't a viable competitor with such well-integrated wearables and the HomePod build quality.