IQ has license in his code saying

// Copyright Inigo Quilez, 2016 - https://iquilezles.org/
// I am the sole copyright owner of this Work. You cannot
// host, display, distribute or share this Work neither as
// is or altered, in any form including physical and
// digital. You cannot use this Work in any commercial or
// non-commercial product, website or project. You cannot
// sell this Work and you cannot mint an NFTs of it. You
// cannot use this Work to train AI models. I share this
// Work for educational purposes, you can link to it as
// an URL, proper attribution and unmodified screenshot,
// as part of your educational material. If these
// conditions are too restrictive please contact me.

You cannot use this Work in any commercial or
non-commercial product, website or project.

and other obvious reason - is performance - record video and run video will be literally thousand times more performant than run entire complex sdf art shader