I've been a full time java developer for the past 7 years. Let me start by agreeing that I have very little interests in the functional "innovations" they added. They're fine, but most of my colleagues agree that code using streams or lambdas very quickly becomes harder to debug then if you just wrote the code with loops and.

That's far from true for every java feature though. Switch statements have been super cool, Green threads are a promising road out of the CompletionStage hell the children are dreaming of these days. "var" is a very nice way to reduce double typing ("Thing x = new Thing()" -> "var x = new Thing()") and also a nice way to avoid changes to unrelated files ("Thing x = getFoo(); f(x);" -> "var x = getFoo(); f(x)" means changing the name of class Thing doesn't require any change to the code) that's been helpful in a lot of cases.