This is a convenient assumption for those who choose to pirate. Even if we assume that it's appropriate to dictate what kinds of contracts artists should or shouldn't enter into with publishers and whether you think they're "strongarmed" or not, this specific scenario only really holds water if you take the time to confirm whether the structure you describe is the one being used in practice before pirating the work.

Self-publishing is growing year over year. More and more authors are publishing their own work on platforms where they get 70% (in case of KDP)-100% (in case of direct sales) royalties. Along with the time to write the actual thing this also usually involves paying out of pocket for things like editors and covers. If you're genuinely committed to this scenario you're describing, I hope you check whether you're actually "taking from robbers" or taking from the author who created the book you're enjoying.