I'd never heard of this! The full name is QuickAssist and it does encryption too. They advertise 100Gb/s symmetric crypto, 70Gb/s compression (or roughly 100x faster than ZStandard on a single CPU). Seems to retail for about $650 for a card.
QAT is actually likely to end up inside new server CPUs from Intel - at least according to the advertising material. Also, it is in their new SmartNICs. At least somebody is using it.
It has been done before, if you offload gzip you turn your PCI bus into a choke point. Most of the time you do better keeping it on the main processor.