Lying is usually legal.

And even if lying is illegal in a particular context, it's de-facto legal since nobody ever gets punished for it.

fraud is not legal. There's a difference between lying on the playground and fraud in a business setting.

Again: fraud is de facto legal.

It is ubiquitous in every part of the business world, both internal and consumer-facing.

De facto is the opposite of de jure, so no, non-enforcement doesn't make it legal

A more useful construct is that civil offenses are only a problem if someone is aware of, motivated, and able to afford to sue you over it. Businesses do a lot of arguably illegal things that are not likely to lead to an actual lawsuit.