Why would we "see" Piaget if his work, as you correctly note, his theories have been refuted? Educationalists, who have never personally and successfully taught anythingmarried simply wrong theories of learning, are a good 50% of the problem.
Most of the broader ideas that he espoused and is famous for were refined in a way that made them accurately generalizable. Typical research timeline where an idea is introduced and is refined over time.
Some of the specific ideas he stated (and typically backed with data) was not generalizable to broader populations and was therefore refuted as an absolute. The data and conclusions were not necessarily wrong for the sample of the population studied, but they were not found to be as broadly true as initially believed.
This additional research led to the refinement of his theories, to great effect, imho.
