As someone who properly learned to program using Java and still works with Java almost every day, I am used to generics. Flexible parameters whose constraints do not yet have to be set during definition. The fact that there are no generics in Go took some getting used to.
The result of the Stack Overflow Developer Survey 2020 has been published and as every year it is quite interesting to take a look at it. But it is also important to note that the survey was conducted in February, before some countries went into lockdown.
While I need to use Java for university projects (currently that are one Spring and one Java EE project) and work, I use Go on some personal projects (Hugo backend and KISSS). While I’m getting more familiar with Go (I do Java for many years), I also experience cases where I actually miss language features from Java. Oh and it’s not generics, I’m currently (still) fine without generics.
Libraries are a bunch of code that simplifies developing of certain features and prevent you from reinventing the wheel. Because most Android libraries are open source it’s also possible to fork and modify them. But you should take care about the specific licenses.