Some prepositions in English would be really hard to learn as a second language. For example you would say "He is IN a movie." and "He is ON a tv show." I guess people would understand you if you said "He is ON a movie", but it just sounds a little off, amirite?
Many languages delegate many meanings to the few prepositions they have, like how French (and maybe other Romantic languages) uses "de" to mean "of" and "from" and for possessive forms also.
Yet, "He's in a tv show," doesn't sound so bad, until you repeat it over a few times.
Superfluous preposition is superfluous.
You're on a bus, on the train, on a plane, in the car
Many languages delegate many meanings to the few prepositions they have, like how French (and maybe other Romantic languages) uses "de" to mean "of" and "from" and for possessive forms also.