I’ve been stalking this page a bit, and finally made an account because this discussion is a fascinating one for me. I have some perspective from the selling side of things in relation to your original comment. I have been doing pottery on and off as a hobby for 15 years. I only just stumbled into bonsai a little over a year ago. The virus led to a severe cutback in hours at work, which led to much more time to do pottery!
I quickly found the Facebook auction sites and decided to start making and selling bonsai pots to try and shore up my lacking income. I can tell you that there is a large gap between what bonsai aesthetics demand vs what sells. The flashy glazed, wheel thrown pots simply do better than the crisp lined unglazed rectangles! I can make 5 wheel thrown pots in the time it takes to make one nice rectangle, but the rectangle won’t sell for much more money than the round. Getting nice clean lines on the wheel is as easy as turning the wheel for a few seconds with a smooth sponge. Rectangles take a much more delicate approach.
This, combined with a large number of imported Chinese mold-made rectangles, just seems to make it uneconomical for me as a potter and businessman to make rectangular pots. If I had a name out there with a following, I could sell for a bit more and make it worth while, but then I could still make more money with flashy glazed round pots.
I have a new job now with only a little time for pottery on the weekends, but I did see another post with a man doing rectangles over a styrafoam form. This method intrigues me greatly, and I think I want to explore it quite a bit more when I get some more time (and when my unheated shed gets warmer next spring!)