To me, it seems clear that NCT, including Dream, is heading to maturity. From Chewing Gum to Boom, they went through a lot and now their music sounds more and more like their seniors in terms of advancement but still keeping their own color.
When you take a track like Boom, released 3 days ago, Contrary to their former tracks, Boom starts with a minimal tone of percussion, less gullible, less colorful. The vibe remains energetic but boldly includes dark synth elements that mainly older bands could have used. As a matter of fact, NCT uniqueness and SME legendary vintage but electronic/futuristic are just effectively blending together to generate a new sound that makes NCT, any sub-unit, noticeable and unique.
The audience will probably keep evolving time passing. Less mainstream, pickier. But NCT counts on quality.
It seems that SME clearly decided to maintain its image of sophisticated - sometimes even dark - vintage high society art provider.
A mix of perfection.