Where should I Go Next?

You don't have a decent system, you have a great system!

No, changing cables won't make a major upgrade.  They can make small changes to the sound of your system.  You may think that small change in extremely important or barely noticeable.

If vinyl is your preferred source, then an upgrade from the VPI followed by a dedicated phono preamp would be a suggested path.  I would caution that it could get costly, say $5k and up.

Consider investing in music, meaning vinyl for you. I did not see anything about vinyl cleaning. Ultrasonic cleaner will possibly increasing SQ more than any piece of electronics.

Last but not least, how does the room sound? 

op

hard to comment on your info without your speaking on what if anything you would like to improve about how the setup makes music

based on what you have disclosed so far my main reaction is ’nice gear, but what about the room?’, the room and placement is about as impactful on sound quality as all the gear combined, at least...

Your streamer/DAC is fine! Going to separates is a sideways move. 

It's all good gear on paper to start.

Standard questions before wasting money on changes:

1)  What is the goal of the upgrade?  What aspect of the sound seems to be lacking?  What is the end goal for the sound?

2)    What attention has been paid to getting the current gear especially speakers set up optimally to make sure you are hearing the best of what you have before making a change?

Hope this helps.