It's not just about having a name listed in an instruction book or in an end roll, and never has been. You know where most TV/film credits are actually seen? On IMDB, Rotten Tomatoes, Metacritic, and other sites. I can go look up my cousin who works in the film industry and see every film he's ever worked on: https://www.imdb.com/name/nm4253724/ That's the primary way that film credits are consumed, and it would be great if we had something similar in our industry (the closest we get is a list of open source contributions e.g. on your GitHub profile). But, for example, I've contributed code to Google Cloud Platform, Android, and the Google Search app, but you'd never know it unless you worked at Google and looked through the monorepo very closely. The closest I can get would be to write my own credits page, but how would anyone verify that?

So it's fine if you don't care, but plenty of other people do care about getting credit for their work, and to them it is quite important. This describes most people in many industries. So yeah, it is important.