the designer has no awareness of supply chain.

Well, you’re asking for a design that boils down to a single channel downconverting I/Q ADC for 21.4 MHz IF, how many such products do you think there are? The ones by TI have been discontinued, your FPGA has no budget to do it and you don’t want one with more oumph so ADI it is … and Mouser says they have 800 on order, so that’s our only option.