Would you rather watch content in your native language, or subtitled? If you read translated content, it's fine. But it's not the same as hearing something performed for you. Might be hard to grasp if your language is largely auditory and written, rather than visual and emotive.
Just because sign language is a visual language, does not mean reading is an equivalent. There is a ton of nuance and feeling that goes into communicating through sign language that is not possible through text alone.
Beyond the communication piece, there is respect of an individual who natively speaks a language, and the importance of keeping the language alive.