There are many series on Netflix that then end in season 2 or 3, but the series actually continues. It's like reading a book, but it never ends.
Sometimes films or series are also built in such a way that there's no end, but that it is so interesting and one wonders how it will go on?
Do you prefer if there's an end or do you find it so exciting when the film / series is finished, but at the end what happened, where you ask yourself how it will go on?
Everyone has to be aware that a series ends at some point, even if it is not so great because you loved watching the series and you want to see more. And it's nice when it has a rounded end. It is somehow clear that the characters will continue but it would be nice if they at least had a good night out. Depending on that, an open end can also fit if it is wanted that it shows, for example, that the fight against evil can never really end, but if it is a cliffhanger because it should go on but not then and you can't make a new ending, it's stupid.
It is similar with films that they want to show that life goes on and that you don't always get a happy ending. Sometimes films also have an open end because a sequel is planned but there will be no further part after all.