The folks with the resources to take an idea, produce it with higher quality materials, distribute it more widely and undercut competitors' costs would be the ones driven out of the market?
Yes because of the overhead and the democritization of technology. If you compare this to the situation today - If you design your own game today, WOTC and other corporations are still the ones with the distribution netork, the publishers etc so it is no worse off for you compared to how it is now. It is worse for them.
To be clear I am talking about intellectual property, not physical things and it would all be open source so you would have access to the same software and tools WOTC uses.
If you are talking about printing books or purchasing say a studio or producing razoer blades, then yes corporations will be able to do that better than individuals, but that is a small portion of the value compared to the intellectual property and while the barriers to an individual competing would be significant, they would be lower than they are now.
WOTC could not prevent others from selling their video games or digital media or any of that.
On a personal level, if you put a painting on canvass that is your painting and no one owns it (unless you sell it to someone), but if you have a digital file anyone who has access to that file can do what they want with it, to include printing a copy on canvas themselves. Further if you do sell it to someone then that physical painting is theirs. They can copy it, reproduce it, burn it in their fireplace, whatever they want.