Which JR pass to buy

I need to go to Kyoto, Himeji, and Hiroshima from Osaka, and between Osaka airport to Osaka. Will be travelling for 5 days, I was looking the Kansai Hiroshima pass BUT it says the Taikaido line between Osaka and Kyoto is NOT covered. So what can I use with this pass to get between Kyoto and Osaka? Or is there another pass that will cover me to go to all these places without having to buy the full national JR pass? https://www.japan-guide.com/e/e2361_kansai_hiroshima.html

The Kansai-Hiroshima Pass will be a good value for your itinerary.

BUT it says the Taikaido line between Osaka and Kyoto is NOT covered.

No, it does not say that! It says that the "Tokaido Shinkansen" between Osaka and Kyoto is not covered. The "Tokaido Line" is covered! Tokaido Shinkansen is not the same as Tokaido Line! In other words: the pass does not cover the shinkansen between Osaka and Kyoto, but it DOES cover all the other JR trains between Osaka and Kyoto, including local, rapid and limited express, just as represented in the coverage map.

That pass is perfect for what you wanna do.

You just cannot use the shinkansen between Osaka and Kyoto. But regular JR trains you can.

Please remember that generally speaking, nobody ever "has to" get a rail pass. In your case though, yes the Kansai-Hiroshima Pass would be a good choice. The bullet train between Osaka & Kyoto is not covered, but the limited express trains like the Thunderbird and regular rapid trains are. It just takes just over 10 minutes more so not a big deal. When timing is not inconvenient, I'd take the limited express train, especially around the rush hour, since it has way far fewer commuters.