But why would it be amazing? The alternative right now is that you do it in software and just dedicate a couple of cores to the task (or even just put in a separate $2 chip to run the decoder).

Like, I get the aesthetic appeal, and I accept that there is a small subset of uses where an FPGA really makes a difference. But in the general case, it's a bit like getting upset at people for using an MCU when a 555 timer would do. Sure, except doing it the "right" way is actually slower, more expensive, and less flexible, so why bother?