With Futures and Executors/ExecutorServices I find that I rarely ever need to use raw Threads these days. Most of the thread-safety issues commonly encountered are eliminated with this approach as well.
They give you the tools to just say "go away and do these things", which after years of dealing directly with pthreads in C was a breath of fresh air!
which presents threads as the solution to the pain of using futures.
A future internally is just a value or a set of waiters. Whether they are "colored" (ie. can you wait on a future in a non-future context), or based on threads or cooperative concurrency (ie. async) etc. is entirely an implementation detail, with significantly differing trade-offs.
In that sense, you can really only compare future implementations with other concurrency systems.
Executors are the way to go for almost all finite-time concurrency.
New threads should normally only be used for stuff that keeps running until the process quits.