AMD's IGP is on the IOD die, Intel's IGP is on the same die as the CPU, AMD's is not on the same chip as the CPU (CCX chiplet) unless you meant the whole package as a chip.
back in the days i compared a Xeon E3-1270 V2 versus a i7-3770 and aside the 8 watts difference between the 2 processor, no other performances differences at all using dGPU with IGP off on the 3770.
i also had no need for an IGP, until i did ... for flashing a GPU... and switching to IGP was faster than getting a weak dGPU, luckily the only time i needed to do so ... i had a i5-2400
well nowadays i have a weak @ss GT730 DDR3 2gb in my i7-3770 "HTPC" so, in case my 6700 XT need a flash i have something
(i will replace it with a RX 6400 GD6 4gb later, so if i upgrade my R5 3600 for a R7 5800X3D i will have something a tad more powerful than Ryzen 4 IGP in case my dGPU go belly up outside warranty clause or periode)