Investors probably demand production limits on FE graphics cards, apparently on some of the lower end models like the RTX 3060 TI FE, they don't make much profit. The thing is, they can set the prices at whatever they like, just add £100-200 onto the price for some models, if not enough profit is being made, then produce 10x more reference model cards (instead of sending the majority of GPU dies to AIBs).
AMD and Nvidia don't discuss reference model production, because they know they could produce a lot more, but choose not to. In fact, we know AMD was considering just not bothering with them altogether for the RX 6000 series. Also, Nvidia stopped doing pre-orders for FE models, which I think has caused a lot of grief and wasted customer's time.