Do I Really Need a Dedicated Streamer?

Nope. I have not, nor will I ever, stream. 

The Wiim products are a great path on which to begin. Just got the pro unit the other day and it works just dandy. It doesn’t seem like it will do the DSD stuff but I’m not to that worry at this time. Also have the Wiim B06 in the other system that works great as well. The Plex app is what transfers the music from the computer to the Wiim units. It works great and is of a low cost. Highly recommended. 

OP, just stay with what you have. Spend extra money on something else entirely for which you know for 100% certainty you are getting something that makes sense to you.

I upgraded from a Squeezebox Duet to Chromecast Audio to Bluesound Node X and to the Auralic G1,1. When streaming from Qobuz, sound quality appear almost as good as when listening to my MD Étude FM tuner. I also use a Chord Qutest and a McIntosh integrated amp.

No, you don't need one, and no, quality will not increase. Even a $7 Apple DAC's noise level is beyond human hearing.