Only posting this 1 time, since it's off topic, but piracy IS a form of theft.
Stealing definition "the action or offense of taking another person's property without permission or legal right and without intending to return it; theft." The last part is key, you can't return something that the original owner still has, hence, it becomes piracy. The law, piracy falls under, is copyright infringement. Here's another definition for theft : "The dishonest appropriation of property belonging to another with the intention to permanently deprive the other of it." Both definitions explicitly state you have to deprive the other person of the property to be classified as theft.
A similar example is if you get a designer to make a logo for a business and they give you the files of the logo and you don't pay them, it's theft since you've taken their work without pay.
Your example is weird, because it's still not stealing. The business didn't steal the files, once again that falls under different laws, I have no idea what because it's not simple copyright infringement. In this scenario, the business commissioned the designer, there was a contract between the two. For example, if the contract didn't state the designer would get paid, it would be perfectly legal, albeit immoral, that the business didn't pay for it. But if it was in the contract that the designer would get paid for it, then the business broke the contract. Breach of Contract law or something or other I dunno.
It doesn't matter that there's no physical object taken, it's still someone's work not being paid for.
Yes, it does matter. Because it falls under a completely different definition if it's digital. Simply because when you steal something in real life, it doesn't leave a "copy", but if you pirate you don't "steal" you "copy" the original files. Unless you deprive the person of their property, it's not stealing. It's so simple really I don't get why people have to constantly equate piracy to stealing.
I'll give you an example too, let's say I hack into Remtairys computer and copy all the development files for Karryn's Prison, that's Piracy as I'm not depriving him of the files. End result, we both have the files but I have it illegally, hence piracy, and it falls under copyright protection laws because it's copyright infringement.
Let's say I delete his files afterwards. End result only I have the files for Karryn's Prison. I deprived him of his property and now only I have it. That's theft, and falls under laws dealing with stealing.
If you wanna argue piracy is stealing because you deprive the owners of profit, then using adblocker means you're a thief.