Am I practicing wrong or right?

[ReneAigner]

The examples I posted are artists who don't use photobashing.

Of course they do. At least Verhasselt certainly uses photos in some pieces and quite a bit of 3D as well.

Vyle also uses 3D and photo elements in his professional work.

Also, you need to make a distinction here between designers and Illustrators. Illustrators need a much better understanding of light and colour than designers do- which is why FZD doesn't teach life drawing/painting at all, but tons and tons of constructive perspective.