Fair enoght, but as i said you cant compare mobile to desktop, they are two completely diferent markets.Really bad seems a bit hard. It's ~14% lower than the 3700X. That's not bad when you consider you get a functional iGPU. Would be be nice if spent some of that cut CU space on cache though. That doesn't seem to stop them from flying off the shelves as coercitiv mentioned.
In desktop you need to consider all the options, and you can buy a 3600 + RX570 for the same money of a 4750G, with that in mind is not that much of a value compared to a notebook were you really need the power efficiency.
To make it short, this whole idea of buying a 4700G and "add a dgpu later" is out of the window with that performance, specially considering the Zen 3 cpus should not be that far away.