Why have only the first few years of nypd blue and hill street blues been released on DVD and not all seasons?

The limited release of only the first few seasons of "NYPD Blue" and "Hill Street Blues" on DVD is primarily due to licensing issues, rights negotiations, and the costs associated with remastering older shows. Additionally, factors like declining demand for physical media and the rise of streaming platforms may have influenced the decision to not continue releasing complete series. These challenges can make it less financially viable for studiOS to invest in re-releasing entire series.