This but unironically. You learn over time how to read subtitles without having to focus on the text. If you’ve ever tried speed reading, it’s a similar skill. You’re not really reading each letter of each word, you’re just kind of absorbing the pattern of the text to help inform how you interpret what you’re hearing.
With worse hearing loss you’ll obviously not be able to rely as much on the audio and will have to focus more on reading, but in those cases I don’t think anyone would argue the subtitles aren’t improving your experience of the video.