I don't know enough about software to contest that statement, but I suspect you could be underestimating the the complexity of what Photoshop does.

We're also talking about multi-gig files. Outside of media the occurrence of an individual application file this large is pretty small. It's not like you can reliably play a 4K video file on many entry-level machines either.

In a similar vein, I would argue that it's a better indictment of the industry that I sometimes have to close Chrome because it's hogging more resources than Photoshop.