Should Every TV Series Have a Planned Ending Before Production Begins?

Some TV shows feel like they know exactly where the story is going from the very first episode, while others seem to keep going until the writers run out of ideas. Having a planned ending could help writers build a more satisfying story, plant meaningful clues early, and avoid unnecessary seasons that weaken the show's quality. What do you think? Should every TV series have its ending planned from day one, or should writers have the freedom to keep a successful show going as long as they have good ideas?