They could have addressed outside the hash but they didn't. They prioritized a big target for over the middle in Klare. Klare was probably the second best big slot option in this draft, to my eye at least. I had Stowers as the top option there. Sadiq I didn't see as a fit or at the very least he is going to need time to develop in the pass game. Klare meanwhile is a player who can plug right in, in that slot role.
Question is whether he's got that intelligence and mentality to feast on the option routes that made Kupp the beast he was in this offense. I certainly would not bet against him. He is very smooth in the pattern, a natural with great instincts in space and he's sudden. Not the athlete the other two were but in that role the athleticism takes a back seat to smooth route running and being able to quickly separate underneath. Him being a big target on top of that is going to endear him to Stafford as well.
And my guess as to what is behind this is the Rams want to keep Nacua healthy. He was a beast in the slot last season, the best player in this league in my estimation. But he gets hurt. So keeping him fresh has to be the plan here. McVay came up short that year in the Super Bowl vs New England primarily because Kupp was out and his offense struggles without a strong slot role. So if Klare or Ferg or someone else can emerge in that role we would then have two deep options for the playoffs. That's my current theory at least.