As much as I'm drawn to languages such as Go that are designed for ahead-of-time compilation to self-contained executables, I don't buy your claim that dynamic languages are particularly susceptible to degeneration. As others have pointed out, Java and C++ are both statically typed, and they've both accumulated considerable cruft over the decades. Go is cleaner primarily because it's newer.
C++ was a mess on day 1 due to the decision to build a sorta-kinda higher level language on a C foundation that was never meant to be used that way. The fact that it was designed by a committee and animated by a philsophy of "features, features, features" pretty much explains everything you need to know about what's wrong with it. Does it really count as degeneration when you're born with the defect?
Java hasn't really acquired that much "cruft." The cruft that it does have is mostly relics of really poor design decisions that were made (again) on day 1. For example, the decision to support thread cancellation, which the designers later realized was dumb, has left a bunch of defunct APIs in the Thread class which you're now not supposed to use. I already talked about how the need for jar compatibility (due to the misguided portability religion) led to the generics issues. Java is an ugly language in some ways, but you can't really say that it degenerated: it was that way from the beginning. In fact, now is probably the prettiest it's ever been (not saying much).
