It's also quite common that the customer is now the one that drives the interface.

It's the customer's time wasted by the UI, but also the customer typically can't be expected to perform enough orders to actually learn a complicated interface.

TUIs persist in industries where there is specialized knowledge needed to even complete the order. For example, an optometrist's office.

I was thinking about employee-facing tools, but I agree that TUIs present an even bigger challenge for casual users / customers.