Speed and fielding has nothing to do with it. Ultimately, it boils down to a need, and how critical that need is compared to other things combatant commanders need from a particular service. The US has far more ways to hit a target (anywhere on the planet) then Israel, and similarly how they do SEAD/DEAD in an Anti Access environment is also going to be different because of resource availability. This means, the USAF can skip fielding an Air Launched Short-Medium ranged ballistic missile and instead pursue capability that it will derive more utility from. And that is just what it is doing with the various hypersonic programs. Similarly, arming an F-16 with a fast missile is less important to the USAF given the size and capability of its bomber fleet. If the USAF had majority tactical fighters, and limited refueling capability it too would have developed a strategy like Israel given a similar threat. The threats though are a lot different (Israel faces nothing like what the US faces in the pacific for example or in EUCOM) and so are the capabilities. As a result, the approach and prioritization would be likewise different. Urgency is usually the result of an urgent need that mitigates an existential threat....
With Russia supplying capable Air Defenses in the region, and Israel's national security need depending upon its ability to strike targets within that environment it absolutely needed that capability. If you look at Israel's neighborhood and its own Air Force, you can tell why it would have invested in this capability rapidly. The US does not face that sense of urgency but one can see numerous examples of urgently fielded equipment in the 2000's when the US did have urgent needs generating requirements in Iraq etc. Similarly, the needs across a diverse set of theaters (PACOM, EUCOM and CENTCOM) and the availability of higher payload carrying aircraft (B-52, B-1 and B-2) means that the USAF can field something that is more capable, longer ranged and designed around more heavily protected targets..I don't think there is any pressing need to arm an F-16 with a Mach 5 missile. The AARGM-ER and SiAW will provide plenty of stand-in and stand off capability with ARRW and other hypersonic missiles providing additional stand off attack capability. As far as urgency in fielding higher end hypersonic systems..just have a look at the test schedule for hypersonic weapons at test ranges in the US over the next 3-4 years. There's been a lot of urgency since 2017 or so to really get out there and field a conventional hypersonic triad.