It was difficult for me to articulate in the original comment and still difficult for me to articulate now. :) Give it a try yourself, Visio has free trials. If you don't see a difference then it doesn't matter!

But it had to do with all of those items being very manual in Draw.io with little assistance. Whereas Visio auto-resized and offered connections and new elements very fluidly.

It seemed like it was taking me 20-30 minutes to do a simple diagram on Draw.io with good layout and sizing when it took me 5 minutes to do it in Visio.