Back when chip costs were reasonable, custom chips would always beat FPGAs and were an easy option for many applications but I think things have changed somewhat in the last few years with the decline of Moore's law. Now there are fewer and fewer companies that can afford to develop custom chips at leading technology nodes. Some estimates are it costs $100m to get a custom chip into product at 7nm. The volumes just aren't there for many applications to justify a custom chip, it doesn't make sense unless the market is huge and the algorithms are static. FPGAs work well in these cases. Have you seen Microsoft Brainwave? https://www.microsoft.com/en-us/research/project/project-bra...