It is not mandatory or contractually based, but
The Next Generation set an unofficial standard for longevity. The series lasted seven seasons, more than doubling the run of
The Original Series.
Deep Space Nine and
Voyager immediately followed TNG, which had seven seasons each. No other series has matched those three since ST: V ended with its series finale,
Endgame. Enterprise barely made it four seasons.
I doubt anyone remotely thought Patrick Stewart would ever match his TNG run with
Picard. I did have high hopes that
Strange New Worlds would easily get the series run standard back to seven seasons. Que sera sera.
It would not surprise me if
Lower Decks keeps trucking along and claims the franchise's series run title. It has already run for five seasons. The format is geared for a young audience and probably appeals to older audiences as well. It is the formula that has kept series like
The Simpsons and
Family Guy running for decades.
I wouldn't know though, since I have never given the show a serious chance. Maybe one day I will. Perhaps it peeves me off
The Animated Series lasted only two years, while something like LD has kept chugging along. Yeah. The artwork was real basic, even by early 1970's cartoon standards. And the dialogue tended to drone on in many episodes, but <expletive>Jim! I LIKED IT!