Visuals compress many details. They make the concept vague for growing minds. For kids, it is too much to handle. Their brain consumes more energy but get hardly any benefit of neuronal connection establishment.
Instead, when the teaching imparted by oral education, kids learn to be more attentive. Attention will allow them to digest detail better and make more and more neuronal connections. Their imagination and memory power increases too. This will have direct impact on their life-long ability to master any new skill or subject.
First 7 years – prefer more listening and involvement. Visual aids are ok but not the primary tools.
And if you wish to use visuals, let there be only one canvas. Mother nature. Let there be vastness of visual inputs. Don’t restrict imagination by gadgets/youtube based education.