Usually not. A film wider than a 16:9 television needs letterboxing to preserve its full shape. The bars allow the entire image to fit without stretching or cropping. Removing them with zoom often discards picture information from the left and right sides.
Compare the shapes
A 16:9 television is approximately 1.78 times as wide as it is tall. Many films use a wider composition. Fitting that width onto the screen leaves unused space above and below. Other material, such as older 4:3 programmes, leaves bars on the sides instead.
Choose composition over screen filling
Watch faces, circular objects and titles before selecting a stretch mode. A filled screen can feel larger while distorting people or cutting off important action. The normal or original aspect setting is a sensible starting point, especially when subtitles sit near the bottom of a wide film image.
Recognise bars built into the source
Some video files include the black area inside their encoded frame. A television then sees a standard rectangular signal even though the active picture is smaller. If bars appear on every side, inspect the player’s fit mode and source rather than applying increasingly aggressive zoom until captions or image edges disappear.