Using subtitles as a supplement really shows how subtitles will just. Shamelessly skip parts of the dialogue. Chunks of sentences just get left out entirely.
There's also the fun thing where Netflix and the like will use the subs that are for the original language translation as the subtitles for dubbed versions.
They are often not even remotely the same and there's been multiple times where my friends and I couldn't understand jokes or references made by each other because I'm relying on the subtitles which don't match the actual audio at all.
Netflix has started using actual subtitles for some of their bigger foreign language movies and shows but not all of them and its infuriating that they only started to do so in the past couple years.