Because, as I ALREADY EXPLAINED, the iGPU has pathetic performance even compared to a VERY LOW END discrete card per the TESTING I did on both my Intel AND my old AMD iGPUs.

 Iris Pro is NOT going to be anywhere close to the performance of the Nvidia GTX 750 ti, much less the MID RANGE 9xx cards.
 The top end Iris Pro iGPU *MIGHT* manage to match my AMD A10-5700 as it has about double the cores of the Intel I did testing on, but that's STILL a sad joke compared to any discrete GPU less than 5 years old.


 Keep in mind that Monero is specifically designed to make both CPUs and GPUs fairly close to equal on performance - nothing else has managed to keep them in the same ballpark to date, and even Monero is failing on that lately to some degree with the Vega (back when they could be found near MSRP).