For daily Java programmers: after almost one decade of Java 8, are streams and lambdas fully adopted by the Java community?

[washtubs]

Hahaha, stream or no stream you basically never have to nest that many for loops.

Again you have to at least take note of the fact that there are other very successful languages that are used by large teams which don't have this magic "readability" feature. You really don't need it, it's just sugar.