Earlier quoted context omitted.
It would be worth it just to have LINQ
Why? The Java Stream API is superior to LINQ in every way, and a lot more extensible. EDIT: Instead of downvoting, please point out how LINQ is actually superior?
How do you extend the the java Stream API? for LINQ you just drop in a few extra extension methods for IEnumerable, IOrederedEmumerable, IQueryable, etc.
How do you reverse a stream in java? (I know you need to evaluate the whole stream for that) You can write a utility method, but that will break the fluent readable logic. In C# you can do the very same thing, with the same method usable as an extension method keeping the readable fluent expression.
Starting a stream is a PITA itself, as it differs for Iterables, Arrays, Collections... Been there, done that. Not that with some utilities these could not be overcome, but it was an inferior experience to LINQ.