Is Pre-Amp needed

A preamp can never make the sound more accurate, it can only degrade

This statement is 100% correct. Going direct, has less distortion and colouration, is more transparent and dynamic.
An added preamp preamp, if prefered can only add colourations/distortions as a "band aid fix" for a "source sound" they don’t like.
Get a better source, instead of putting a very expensive bandaid on it. "The best preamp is no preamp."

Cheers George

Re the accuracy debate: interesting comment in Stereophile from one of the writers. He quoted JGH as having said something along the lines of...Accuracy is something all audiophiles say they want, but when they get it they don't like it.

So...maybe using a preamp is less accurate, but it sure sounds better to me.

I will never use a preamp again. 

Based on my limited experience, preamp is most important part after your speakers. You can read all the numbers and statements that logically sounds correct but if you add a good preamplifier, you understand why people use preamps.
p.s)Some DACs equipped with a in built preamp but still I prefer a separate preamp specifically a tube preamp!