There's really no point in killing the US title, honestly. Especially if you eliminate the WHC. Having two midcard singles titles has always worked well. Even having the European title worked when there was only one WWE Championship. There's nothing wrong with having two champions who are both regarded as lower-tier champions to the one true WWE Champion. I really haven't read any good arguments to suggest the US Championship is unnecessary. It's not simply a "WCW title" either as some have put it. It's lineage dates back to pre-WCW in Mid-Atlantic. Several wrestling legends have carried that title and it would be a shame to see it retired "just because". Tradition is a big deal to me, both in wrestling and sports, and retiring that belt for no good reason would just infuriate me.
The WHC, on the other hand, has no such merit. Just about everyone who has won the WHC and is a wrestling legend or at least on-pace to become one has held the WWE Championship as well. And it really can't be hammered-home enough that the belt was only created in the first place to coincide with a brand-split which isn't being honored the slightest anymore. I love the belt's design, and it's arguably the prettiest design for any wrestling championship belt ever, but it's still not the WCW Championship that it was modeled after and doesn't carry nearly the prestige or importance that belt carried. I would be more on-board with keeping it around if they simply never got rid of the WCW Championship in the first place, made a smaller knock-off version of it, and called it the "World Heavyweight Championship". At least with the WCW Championship, you could argue that belt's lineage all the way back to the 1900's, although some still suggest it was birthed in the 1990's when Sting won it. Either way, it would still be a lot more prominent than the WHC.