If you haven't been able to carve out that distinct niche for yourself, either in the work you do, how you do the work, or who you do the work for . . . then you are officially a commodity and you will be treated like one, meaning you will get paid just enough to keep you working but never enough to be stable. It's true for doctors, lawyers, plumbers and artists . . . there is nothing sacred about the artistic profession that makes it different.
I'm going to put aside the idea that any human being should be treated like a commodity, and not discuss the moral bankruptcy that such a system exhibits. Instead, I am going to focus on the fact the commodification happens to "doctors, lawyers, plumbers..." There is at least one difference between this group and theatre artists, and I think it is important: there are over 1 million lawyers in the United States, about 837,000 doctors; there are 46,000 members of Actors Equity. So the idea that there is, at least comparatively, an oversupply of actors might be an over-statement. But what is key is that the lawyers and doctors are spread all over the nation. There probably isn't a town so small that it doesn't have at least one attorney or doctor. And yet there are six states that have no TCG member theatres at all, and 11 more that have only one. In addition, what would be the impact on the legal or medical profession if most members of it were centralized in a single city? What would happen if someone in Marshall, NC had to bring in a lawyer from New York to do their will? It is hard to predict, but I suspect what would happen is that some other way of doing things would develop. Small towns might develop "community lawyers" on the order of community theatres, where someone local provided the services themselves. This would especially true if there were no laws set up that required that licensed lawyers do the work.
The point is that what seems like lack of scarcity in the acting profession may, in fact, be an over-concentration of actors in a few areas. Ethan Stanilslawski, in a post summarizing the dialogue on this topic, writes "A bad lawyer can still make six figures, while an exceptional one can make eight figures. Theater artist should be able to make a living the same way." While I know I am not arguing on behalf of "bad artists," and I doubt that Mike is either, I would change the focus from quantitative issues to geographic: a lawyer in Marshall, NC can make six figures, and one in NYC might make eight figures." (Of course, six figures in Marshall might be the equivalent of eight figures in NYC, but let's set that aside.) My argument is that more artists could make a living in the theatre if the theatre had more geographical diversity. And in that instance, we could break out of the high-stakes poker model to one more like...well, lawyers and doctors, or at least plumbers.