While raw performance is comparable to a Core i5-8300H as designed, the Ryzen 7 3750H offers almost no tangible benefits over the Ryzen 5 3550H. The performance differences are so incredibly minor between the two SKUs that AMD could have just launched with one SKU only to make life simpler.
https://www.notebookcheck.net/Not-worth-it-AMD-Ryzen-7-3750H-is-only-8-percent-faster-than-the-Ryzen-5-3550H.426841.0.html