Not just that. Video codecs are insanely hard to get right even in software, FPGAs capable of running a decoder are expensive, the intersection of "people who know video codecs" and "people who know Verilog" is pretty small, and a decoder has to support a lot of leeway in ingestion to allow for others' buggy encoders... and if you're also making encoders, shipping bad hardware encoders at scale will kill your reputation as now everyone else has to deal with implementing quirks for your bad content.
That means developing and testing an ASIC encoder or decoder block is one hell of an expense. If you're someone like Apple with more cash than the GDP of many countries or if you're making an implementation of a codec that is a worldwide standard (like h264/h265 are) and you can simply make your profit on selling billions of chips, you can do this. But everyone else can't.