That is true of all languages, but I think that Cantonese has a particularly high change velocity in terms of vocabulary and pronunciation compared to, say, English.
I think this is because Cantonese speakers tend to read and write in Modern Standard Chinese (more like written Mandarin) and so are much less anchored by the permanence of text. Additionally, Chinese characters provide even less guidance on pronunciation than English spelling. In this landscape, Hong Kong's small media ecosystem is a fertile breeding ground for new language.
I think this is because Cantonese speakers tend to read and write in Modern Standard Chinese (more like written Mandarin) and so are much less anchored by the permanence of text. Additionally, Chinese characters provide even less guidance on pronunciation than English spelling. In this landscape, Hong Kong's small media ecosystem is a fertile breeding ground for new language.