It kind of has? People believe written words when they come from a source that they consider, erroneously or not, to be trustworthy (newspaper, printed book, Wikipedia, etc.). They trust the source, not the words themselves just due to being written somewhere.
This has so far not been true of videos (e.g. a video of a celebrity from a random source has typically been trusted by laypeople) and should change.
It is always the others that believe in false information. "The stupid people", I guess. This is a completely fictional perspective that there are masses convinced and led astray by misinformation on the internet.
Misinformation only works if it confirms what people want to believe already. That there exists or not exists such material is secondary at best. But well, that is off topic I guess.
People believe plenty of just written words - which are extremely easy to "fake", you just type them. Why has that trust not dropped to about 0?