The mainstream approach that really made a hash of things though was "Whole Language" learning, largely commercialized by Fountas and Pinnell, which eventually provided the program and associated materials to classrooms around the world. This program relied, in part, on guessing: if a child got stuck on a word, they would be asked to guess what word might fit in the sentence. Sometimes they were given context clues, like a picture on the page. Any efforts to associate individual letters or letter combinations with sounds was abandoned.

Wikipedia has something of a watered-down overview of this at https://en.wikipedia.org/wiki/Whole_language, but I really recommend listening to the podcast in the second link in my parent comment (https://features.apmreports.org/sold-a-story/), APM Reports put together a compelling examination of what happened, and it's explained well. (I do wish it was also available in a more typical article format.)