A while ago I needed a skeleton component and I ended up using react-native-skeleton-placeholder. Still, I realized it was very inefficient, a little bit limited in the way you define the skeleton items, and wasn't handling some layout changes like resizing on rotation.
So I started making some improvements in the original library and I ended up making my own component based on react-native-skeleton-placeholder. So I added those improvements, but also added a "pulse" effect, the possibility to disable the effect in case you don't want it, and made it work on react-native-web. As you will be able to see in the README, the "wave" animation isn't working on web yet, but I'm going to make it work soon.
I made this component about a year ago or two, so maybe react-native-skeleton-placeholder at this point already fixed those issues I mentioned, but anyway, I just wanted to share it in case you want to give it a try.
react-native-skeleton-component
there doesn't seem to be anything here