I am not to fond of Shostakovich, never have been. Every time that hear the term, cognitive dissonance, I think of his music, or what he calls music.
Or Phillip Glass.
Shosty wasn’t nearly as dissonant as his contemporaries. What do you think of Strauss’ most dissonant music not to mention Mahler and Schoenberg.
I would encourage you to listen again to his chamber music; piano music, string quartets, etc.
The symphonies can be a little "tendentious" in the view of some.
On the other hand, I think the string quartets are probably the most beautiful and inspired pieces of chamber music since late Beethoven. No. 8 in C minor is a masterpiece that will last forever, IMHO. Really breathtaking.