Agreed. Darker than TNG and lighter than DS9.
I agree that DS9 is the gold standard for Star Trek in many ways, however, "quality" is not mutually exclusive to "darker." I think Deep Space Nine was a much needed evolution in Trek's writing and maturing process to stay relevent. I also believe Discovery and Picard are also evolutionary steps in that CBS is focused on making the franchise competitive. Part of that is these shows have to be sought out and paid for to see. These new offerings pretty much operate on commission rather than salaried (like network shows … how's that for a metaphor?).
Another sign of the times to contextualize Discovery and Picard: DS9 was penalized for its relative sophistication and complexity by lack of studio support and promotion while the recent CBS offerings are embraced and heavily promoted.