While KEH was great for used camera gear (I haven't bought new or used gear in ages so IDK how they are now), B&H offers an unmatached breadth. If anything I'd say that Adorama is a much closer competitor to B&H, although I'm loathe to buy from Adorama due to the incessant spam I get from them every time I make a purchase.

Yes on both counts. KEH is mostly used photo gear and they tend to be my go-to for that although, like you, it's a rare purchase for me. I tend to default to B&H but I'd agree their closest competitor is Adorama (although B&H's store in Manhattan is much larger).