Whenever I click on a link or a button, it takes a little while to load. Not too big of a deal, but if I didn't know better, I'd think that I didn't actually click the button. Or that something is broken.
A loading indicator would be perfect for letting users know that the button was indeed clicked and the content is being loaded.
((If it matters, I'm accessing Nativshark with my Google Pixel 3XL using Chrome.))