The Androids book by Chet Haase provides a good look at the early history and design decisions of the platform and how they came to be made.
At the time there was a debate inside the team over what language their app development framework should use, with native C++ and Java being the two main options (I think there might have been another option or two, I can’t recall). In the end Java won out, and from memory one of the main reasons was to make it easier to make apps and not need to think about the lower level parts of the platform, i.e. the platform takes on the complexity internally in order to lower the barrier to entry for app developers. The idea being that a lower barrier to entry would result in more apps being developed for the platform. For a brand new platform that lives and dies by the apps available for it, that’s a pretty sensible trade-off.
And yes, Android has a lot of vestigial remnants of the past, the Android framework team has been very particular about maintaining as much backwards compatibility as possible within the framework.