Going all the way back to the USN's second carrier, USS Lexington, CV-2, the speed of US carriers plus the range to which their planes could carry ordnance were what made pre-Treaty battleships all but obsolete (that they carried 10 or 12 or ?? heavy AA guns and their ability to lob huge shells by the scores or hundreds 25 miles inland was still very valuable). IIRC, USS Ranger (CV-4) and USS Wasp (CV-7) were capable of 29 Kn, the slowest carriers the USN had in WW2. The rest could all do well north of 30 Kn.
Hull forms, propellers, and propulsion plants have advanced incredibly since the 1940s, to the point that the true top speed of USN carriers is something they won't publish.