I think that’s more of an issue with OLED being really expensive. From what I’ve checked going from 16:9 IPS to 21:9 IPS should be roughly the same the price increase (percentage-wise) as going from 16:9 OLED to 21:9 OLED. Besides the bigger screen simply costing more going from 16:9 to 21:9 doesn’t really increase the cost of the monitor. It’s just the OLED itself that makes it cost so much, at least in theory.
I think that’s more of an issue with OLED being really expensive. From what I’ve checked going from 16:9 IPS to 21:9 IPS should be roughly the same the price increase (percentage-wise) as going from 16:9 OLED to 21:9 OLED. Besides the bigger screen simply costing more going from 16:9 to 21:9 doesn’t really increase the cost of the monitor. It’s just the OLED itself that makes it cost so much, at least in theory.