[barskern]

> And don’t over use viz. [...]

I don't fully agree with this neither. Especially for mathematical concepts, visualization can give insight into how theorems are constructed and combined. This can prove to be vital when applying concepts and theorems to new problems.

I would especially like to bring forth 3blue1brown[1]. He is a creator of videos which beautifully visualizes and explains complex mathematical problems. His efforts has given me an insight into math which theorems explained in text and variables could never do.

However I do see your point that visualizations without understanding can be misleading. Hence the pure, written math is important to read and reason about, but I do believe that some concepts need to be visualized to be fully understood.

[1]: http://www.3blue1brown.com