> Integer arithmetic is still simpler to implement in hardware and therefore faster than floating point arithmetic

This is true in the abstract, but not necessarily true of a specific commodity chip. Processor vendors spend a lot of silicon on offering low latency and high throughput floating point support. It's a fairly recent trend of processor vendors adding fast int8 or bfloat16 vectors after the ML craze demonstrated that there was demand for vector support for more bandwidth-friendly datatypes.